IT Revision Flashcards
ASCII
American Standard Code for Information Interchange
the type of code that tells your keys which characters you are typing, offering 128 characters, with one bit per character
ADC
Analogue to Data Converter
creates digital sound signal in microphones
Analogue Input
converts a voltage level into a digital value that can be stored and processed in a computer
Analogue Output
a continuous output from PLC to field devices
And
a conjunction
only when both statements are true can the end result be true
straight line one, likes 0s
ALU
Arithmetic Logic Unit
performs all the mathematical calculations and logical operations in the CPU. Makes logical decisions and returns the answers to a temporary stage register known as the accumulator. A number needs to be inputted to be processed and a code from the controller which gives the operation to be performed
Arithmetic Shift Functions
multiplications of bit patterns, which involves moving the bits in a specified direction, either left or right, a number of places
Backing Store
Retains data written on it after the computer is switched off
Includes hard disks, flash drives, removable disks
BIOS
Basic Input Output System
a chip that enables a computer to communicate with other devices (eg keyboard, disk drive, monitor) on start up
Binary Digits
Either a 1 or a 0
Nybble
4 bits
Byte
8 bits
Kilobyte (Kb)
1024 bits
Megabyte (MB)
1024 KB
Gigabyte (GB)
1024 MB
Terabyte (TB)
1024 GB
Petabyte (PB)
1024 TB
Exabyte (EB)
1024 PB
Zettabyte (ZB)
1024 EB
Yotabyte (YB)
1024 ZB
Boolean
statements that can be true or false
Absorptive Law
allows complicated expressions to be simplified by absorbing terms
A+(A.B)=A, A(A+B)=A
Annulment Law
states that and always equals 1, and or always equals 0
A.0=0 A+1=1
Associate Law
states that statements can be rearranged
A+(B+C)=(A+B)+C=A+B+C, A(B.C)
Commutative Law
states the order of conjuctions/disjunctions does not matter
A.B=B.A A+B=B+A
Complement Law
states that a term anded with its complement equals 0 and a term ored with its complement equals 1
A.NotA=1 A+NotA=0
Distributive Law
states that the order of brackets matter, however the contents of the brackets’ order doesn’t matter
A(B+C)=A.B+A.C A+(B.C)=(A+B).(A+C)
Double Complement Laws
states that the double complement of a variable is always equal to the variable
Impotent Law
states that an input that is anded or ored with itself equals itself
A+A=A A.A=A
Identity Law
states that if a term is ored with a 0 it will always be a 0/ if a term is anded with a 1 it will always be a 1
0.1 = 1 0+1=0
Bridge
A computer networking device that creates a single aggregate network from multiple communication networks or network segments
Brouter
Does the work of a bridge and a router
Bus
something that connects the processor to another part of the computer
Address Bus
where the address of the data is communicated to the main memory. The width defines the amount of physical memory that can be addressed
Control Bus
used to tell the memory or the device the operation that is to be formed
Data Bus
a series of processors that connects the processor the main memory (RAM) or cache memory. Can be used to read from or write to the memory.
Capacity
the quantity of data that a storage medium can hold
Central Processing Unit (CPU)
main processor that executes instructions in a computer
Clock Speed
the speed at which a processor operates
Overclocking
when the process is set to run faster than the original design and overheats
Underclocking
when the process is set to run slower than the original design
Cores
a term used to describe the processing components within the CPU. Multi-core processors therefore have many processing components within the same CPU. These can be dual-core or quad-core.
Dual-Core Processor
in theory, a processor that processes twice as fast as single-core
Quad-Core Processor
in theory, a processor that processes four times as fast as a single-core processor
Cache (Memory Type)
a fast access type of memory that is very expensive and is able to provide instructions and data to the CPU faster than memory systems
L1 Cache
Smallest and fastest cache
L2 Cache
Larger and slower than the L1 cache, instructions are searched for in here if not in L1
L3 Cache
Largest and slowest cache, instructions are searched for in here if not in L1 or L2
Cache (Disk Type)
a hard disk that is not part of the normal array
Character
single character, eg H
Colour Depth
the amount of red, green and blue in each pixel
Computer Port
hardware that interfaces between the computer and other computers in peripheral devices
Audio Port
connector to plug ANALOGUE audio signals into a computer
Digital Visual Interface
to connect a video source to a computer monitor
Ethernet
mainly used for network and internet connectivity, carries broadband signals between different wired internet-capable devices
HDMI
High-Definition Multimedia Interface
used to transfer audio/visual data to compatible monitors/IDTV/video projectors
IEEE1934 Interface/Firewire
used for high-speed data transfer
PS/2 Connector
a six-pin connector used to connect mice and computers
Universal Serial Bus (USB)
allows high-speed connectivity with peripheral devices
Computer System
operates with hardware and software to create a functional solution
Controller
fetches instructions, translates and decodes them and then manages the execution of these instructions. Controls fetch-execute cycle
Control Unit
directs the flow of instructions and/or data or coordinates to other parts of the CPU, also generates clock ticks or controls the clock
Data
a set of raw facts and figures that have no apparent reasoning
Data Capture
the name given to the input of data into the system in a suitable format
Digital Input
detects if a voltage is above/below a specific threshold
Data Output
allows you to control a voltage with a computer
DNS
Domain Name System
a distributed database that matches IP addresses to computer system resources, for example, to give a domain name Google instead of 173.194.34.191
Durability
how susceptible something is to damage
Dynamic Host Configuration Protocol Server
a server that allocates IP addresses
Embedded System
a combination of software and hardware that performs a specific task rather than a general-purpose computer that is designed to carry out multiple tasks. Often control real time events so must be completely reliable. They are embedded in firmware and stored in read-only memory. Most react to conditions such as temperature, weight, vibration and air quality, detecting external conditions and reacting to them by recording data, turning motors on or off, sounding an alarm or sending a message to the processor
Encryption
means that data can only be read by someone has the same decryption software on the other end (e.g. like on WhatsApp)
Fetch-Execute Cycle
Fetch-Execute Cycle – made up of three steps for processing instructions by a currently running program:
1. The fetch cycle takes the address required from the memory, stores it in the instruction register, and moves the program counter on one so that it points at the next instruction.
2. The control unit checks the instruction in the instruction register. The instruction is decoded to determine the action that needs to be carried out.
3. That actual actions that happen during the execution cycle depend on the instruction itself.
Fibre Optic Cable
cables with many optical fibres inside plastic casing which transfer data in the form of light
a single keystroke
1B
a number from 1 to 255
1B
one line of text
70B
a short e-mail
1KB
a third of a page of text
1KB
a small picture
8KB
a basic webpage
30KB
maximum size for all elements of a webpage
100KB
a five page word document
500KB
a PDF for downloading
500KB
a minute of audio when stored as an MP3
1MB
a DVD film
5MB
an HD file
10MB
a Blu-Ray film
25MB
maximum amount of data on one CD-ROM
700MB
Full-Duplex
allows more than one person to transmit data at once
Half Duplex
only allows one person to transmit data at once (e.g. on walkie-talkies)
Gateway
a piece of networking hardware used in telecommunication networks that allows data to flow from one discreet network to another
Graphics
visual images produced by computer processing
Bitmap Image
a type of raster image that is composed of many tiny parts, called pixels, which are often many different colours. It is possible to edit each individual pixel
Raster Graphics
dot matrix data structures representing a grid of pixel which cannot scale up without loss of apparent quality. They tend to need a lot of storage
Vector Graphics
allows the graphic to resize without losing quality, unlike the other two. This is because they use geometrically primitive objects such as points, lines, curves, shapes or polygons which are based on mathematical expression to represent images
GPU
Graphics Processing Unit
a microprocessor that performs the calculations needed to produce graphic images on screen. Initially the CPU performed these calculations, but as more complex applications were developed, such as 3D graphics and video quality animations, the GPU was introduced to offload those tasks from the CPU. GPUs can be integrated within the circuitry of the motherboard or provided on a dedicated graphics card.
Integrated GPU
uses the computer’s RAM. Is cheaper than installing a dedicated GPU, it generates less heat and uses less power. They are perfect for general graphics processing such as watching or editing videos and word processing
Dedicated GPU
has its own video memory, used by people such as professional graphic designers and serious gamers, but use more sound and require a good cooling system
Sound Card
may be on the motherboard or designed to fit a PCI slot. Enable the computer to output sound through speakers, to record sound from a microphone and to manipulate sound stored or a disk. Sound cards convert analogue input signals into digital data and reverse this process for audio output.
Mono Card
a sound card that only allows one channel for multiple speakers
Stereo Card
a sound card that allows multiple channels for multiple speakers
Hardware
physical parts of a computer system, needed to gain a usable output from the system
Hub
node that broadcasts data to every computer or ethernet-based device on a network
HMI
Human Machine Interface
the user interface that connects an operator to a controller for an industrial system
Implicaton
the relationship between two statements
Information
data which has been processed and is given a meaning
Input Device
where data is inputted into the system e.g. keyboard, mouse
Integer
whole number
IP Address
Internet Protocol Address
an address allocated to a computer system on a network, used to uniquely identify systems on a network, allowing communication between them
Lossless Data
a way of compressing data without removing parts
Lossy Data
a way of compressing data by removing parts
MAC Address
Media Access Control Address
a 12-digit hexadecimal number that is most often displayed with a colon or hyphen separating every two digits to make it easier to read. It is a unique identifier for network interfaces
Memory
the part of a computer where data or program instructions can be stored for future use
Cache Memory
a small memory store used directly by the CPU, holds copies of the most frequently used instructions and data, reduces access time and speeds up processing; is volatile; data can be changed; is very fast
Flash Memory
is solid state (adapted from EPROM), composed of a series of logic gates that hold data in a non-binary format, now often used to replace ROM chips, involved in read/write only devices. Is permanent. Can be very slow. Data can be changed.
RAM
Random Access Memory
Allow multi-tasking so it is possible to have multiple programs running at once, holds data for programs currently being executed, editable, volatile
ROM
Read-Only Memory
Memory that is uneditable, non-volatile and controls functions such as what the computer does on start up
Virtual Memory
incorporates paging and swapping and is a memory management technique that gives the illusion of a very large main memory by moving data out to slower media e.g. a disk when it is not being used. Is used when RAM is full, uses the hard drive to temporarily store RAM content, causes system to slow down and stores programs and data not currently in use and retrieves them when required.
Metadata
data about data e.g. height and width of images
Microprocessor
an integrated circuit that contains all the functions of the CPU
Most Significant Bit
the bit that decides whether a number is positive or negative, where 0 is positive and 1 is negative
Motherboard
main circuit board of the computer. The CPU and ROM will be mounted on the mother board, which also provides RAM expansion slots, USB ports, PCI slots for expansion cards and controllers for devices such as the hard drive, DVD drive keyboard and mouse.
Negation
a unary argument i.e. it is not
Network Interface Card
provides a computer with a connection to a network
Network Protocols
allows computers on networks to communicate
Wi-Fi
wireless
two common standards are Bluetooth and 801.11
TCP
Transmission Control Protocol
popular communication protocol that is used for communicating over a network and divides any messages into a series of packets that are sent from source to destination where it gets reassembled
IP
Internet Protocol
an addressing protocol and is often combined with TCP to use a series of packets
HTTP
Hyper Text Transfer Protocol
allows webpages to be shared
HTTPS
Hyper Text Transfer Protocol Secure
allows webpages to be shared securely
POP3
Post Office Protocol 3
most commonly used for receiving e-mails over the internet
SMTP
Simple Mail Transfer Protocol
allows transmission of e-mails on a computer network
IMAP
Internet Message Access Protocol
transfers messages between computer systems via the internet, generally used for retrieval and storage
Octet
a group of two digits in a MAC address
OSI Model
Open Systems Interconnection Model
model that characterises and standardises the communication functions of a telecommunication or computing system regardless of its internal structure
Applications Layer
tells the computer how data is going to be used
Presentation Layer
tells the computer how to change data to a form that can be read
Session Layer
tells the computer how the data is exchanged (e.g. half or full duplex)
Transport Layer
tells the computer how the data is going to transported, broken up and put back together
Network Layer
tells the computer how things are sent across e.g. traffic control, uses internet protocol, keeps addresses of different computers to each computer, decides routes which data takes
Data Link Layer
tells the computer how data will be carried e.g. how quickly
Physical Layer
the raw bit that streams over a physical medium (e.g. Bluetooth, Ethernet, USB)
Operator
the part of computer instruction which specifies how the data is to be manipulated
Operand
the part of computer instruction which specifies what data is to be manipulated or operated on, whilst at the same time representing the data itself
Output Device
where information is presented in a logical form
Overflow
the result of an addition or shift process if the number it results in is too large to fit in the space avaliable
Underflow
the result of a subtraction or shift function where the number it results in is too small for the space avaliable
Packet
a collection of data that is transmitted over a packet-switched network. These are provided to a network for delivery to a specified location. Each packet of data is redirected by a computer system along the network until it arrives at its destination. Data may be split into several packets. When all packets have arrived, the data is a reassembled.
Packet Switching
the process of delivering packets from one computer system to another
Peripherals
devices not mounted on the motherboard, such as input and output devices
Pixels
Picture Elements
small coloured dots that make up graphics
Portability
the ease with which a secondary storage medium can be connected from one device to another
Power Supply
used to convert Mains Alternating Current to low-voltage Direct Current for the various components of the system
Process
where data that is inputted is converted into a suitable format
Protocol
the agreed-upon format which allows two devices to communicate
Handshaking
where two devices establish their readiness to communicate, normally part of a protocol
Protocol Stacks
a set of network protocol layers that work together
Real Number
a number with or without a fraction
Register
a storage location found in the CPU where data or control information is stored temporarily. Usually much faster to access than internal memory
Accumulator
temporary state register that has data from the ALU sent to it
CIR
Current Instruction Register
the part of a CPU’s control unit that holds the information currently being executed
Internal Memory
the memory that is available within the CPU
Internal Register
one type of internal memory, used by the processor in conjunction with fetching information from the RAM
User Accessible Register
these are used within programmable instructions
MAR
Memory Address Register
the CPU register that stores the memory address from which the data will be fetched to the CPU
MDR
Mobile Data Register
used for holding information (either program words or data words) that is in the process of being transferred from the memory to the central processor, or vice versa
PC
Program Counter
a processor register that indicates where a computer is in its program sequence
Reliability
how likely something is to fail through continuous use
Router
a networking device that forwards packets between computer networks and performs the traffic direction functions on the internet
Routing
the name given to the method of selecting paths along which packets are sent on a computer network
Static Routing
where the data travels to its destination along a pre-set path. This is straightforward to implement, but may take longer
Dynamic Routing
where data travels to its destination where data packets can take different routes. This is complicated to implement but quicker than static routing
Sampling Rate
the number of samples taken per second from the analogue input to create a digital signal. The higher the sample rate the larger the file size
Sampling Resolution
the number of bits used to store each sample. The larger the number of bits used, the larger the file size
Searching algorithms
used by computers to search for a value in a given list
Binary Search
a more efficient way of soring that only works on sorted lists which starts by finding the middle item and comparing it to the value it is searching for; if the middle value is smaller than the value it is searching for then the first half of the list is removed, including the middle value. If the new middle value is larger than the value it is searching for then the top half of the list is removed, including the middle value. This process is repeated until the value is found.
Linear Search
goes through each item in an algorithm one by one until it finds the one it is looking for, then it stops the search after potentially going through every item in the list
Secondary Storage
non-volatile, long-term storage
Optical Devices
uses technology such as lasers
Blu-Ray Disk
laser beams are projected onto the disk and if they are reflected back the data is recorded as a 1, if not, a 0. Blu-ray has more storage than CD or DVD.
CD
Compact Disk
laser beams are projected onto the disk and if they are reflected back the data is recorded as a 1, if not, a 0. CDs have less storage than DVDs or Blu-ray disks.
DVD
Digital Versatile Disk
laser beams are projected onto the disk and if they are reflected back, the data is recorded as a 1, if not, a 0. DVDs have more storage than CDs, but less than Blu-ray disks.
Magnetic Devices
uses technology stored in magnetic mediums (e.g. external hard drive, magnetic hard drive, magnetic tape)
Solid State Devices
Called solid state as it does not have any moving parts, unlike the other two. This is increasingly being used to replace but optical and magnetic devices, especially in mobile phones, where its low power consumption and speed is advantageous (e.g. flash memory, solid state drives)
Solid State Drives
an electronic storage unit built on solid state architecture
Storage in the Cloud
a contemporary storage facility that allows users to store their data on third-party servers. They can then access that data from many computing devices.
Speed
the access time to transfer data onto the secondary storage medium
Software
actual programs that make the computer run
Sorting Algorithms
something a computer uses to set unordered lists and values
Bubble Sort
works by working through a list, comparing pairs and values and swapping them if they are in the wrong order. Is simple to implement but is very inefficient.
Merge Sort
works by splitting the lists into individual values and gradually merging them to form bigger lists until they are all in one sorted list. Is one of the most efficient when used with both big and small lists.
Standards
manufactured following sets of rules, agreed amounts of data loss
String
more than one character
Switch
similar to a hub, but is able to tell which devices to broadcast traffic to
Truth Table
a diagram that shows all possible logical inputs and their associated outputs
Unicode
a sixteen-bit character set with 65536 characters available, allowing it enough characters for any writing system. This is the standard character set and is used by all major web browsers and applications. It uses more storage than ASCII, with two bits per character.
Wireless Access Point
an access point is a device that creates a wireless local area network. These are normally wireless.
Topology
a way in which network devices are arranged
Star Topology
where computers are connected separately to one hub or switch in the middle
Bus Topology
where computers are connected in a line, also known as daisy chain
Ring Topology
where computers are connected in a ring
Hybrid Topology
where each computer has more than one route for data to take, most common form of topology
Xor
For when conditions are exclusive
RISC Processor
Reduced Instruction Set Computer
Processes a limited range of simple instructions and needs to break down complex commands into simpler ones to carry them out, but runs cooler, uses less power and are cheaper.
8-bit Colour Depth
256 colours
Assignment
The process of setting the value stored in a variable
Decomposition
breaking a problem down into a number of sub-problems
Selection
where a value is assigned a variable, normally in If, Then, Else statements
Data Type
defines the range of values a variable may take
Concatenating
joining variables together
Define subroutine
Declare CapitalLetterOfName
End Subroutine
Call a routine
call SubroutineNeeded
Declare and use arrays
myarray[99]
Literal outputs
output “Please enter a number”
Variable names
myvariable
Define variable data type
myvariable is integer
Data types
integer, character, string, boolean
Assignment
set counter = 0
Selection
if … else … end if
Comments in Java
/** Comments for Java */
Repetition
for i … next i
repeat … until
do … loop
do … while
while … repeat
Flowchart
a way of designing an algorithm that uses different shapes to represent different types of instruction
Pseudocode
a way of designing an algorithm in programming-type statements that are not specific to any programming language
Oval (in flowchart)
start/stop
used to show where the beginning and end of our flowchart is
Parallelogram (in flowchart)
input/output
used to demonstrate where a flowchart will take in an input, or provide an output
Rectangle (in flowchart)
Process
used to show any processes or calculations that are happening in our flowchart
Diamond (in flowchart)
Decision
used to demonstrate a decision or choice that needs to be taken in our flowchart, which will have a ‘yes’ and a ‘no’ path from the decision symbol
Arrow (in flowchart)
Arrow
used to show the flow of data through our flowchart
Circle
Connector
used to connect parts of the same flowchart that are drawn in different places, such as on different pages
Condition
a feature in an algorithm that can be met or not met, causing a different action to be taken
Loop
a sequence of instructions that is continually repeated a set number of times or until a condition is met
Sequence
the order in which a set of instructions is carried out in an algorithm
Selection
a way of creating multiple paths and decisions in an algorithm
Variable
a named storage location that contains a value that can change during the execution of a program
CamelCase
wayOfwritingVariables
Repetition
a way of repeating a set of instructions in an algorithm
Count Variable
a variable containing an integer that counts how many times a loop has run
Self-Documenting Identifier
any name that you give to a subroutine or a variable that makes it clear what that subroutine or variable is for
Annotation
comments written in plain English that are ignored by the compiler and are there to help a programmer and other people who read the code understand it
Object
a representation of a real-world thing
e.g a library program may contain millions ‘book’ objects
Classes
a template for an object, specifying attributes and methods that belong to each object
e.g the library program would only contain one book class, using which many book objects would be created
Methods
subroutines that belong to a particular class, that can be run on any object created from that class
e.g. the book class, for example, might have a method called ‘borrow’
Attributes
variables that belong to a particular class
e.g. attributes in a book class would include author, title, number of pages, date of publication
Subroutine
a named set of instructions that can be called to run from elsewhere in the program, such as procedures and functions
Local Variable
a variable that is declared within a function or procedure and can therefore only be used within that function or procedure
Global Variable
a variable that is visible throughout the whole of the program
Normal Data
typical data that a computer program would be expected to accept
Erroneous Data
deliberately invalid data entered to check that the program does not crash, and that error messages display correctly
Boundary Data
test data that is on the very edge of a range of valid data
Validation
process to check whether something is correct or not
Verification
process to check whether user entries are correct
Data Handling
collecting and presenting data
Data Processing
the collection and manipulation of data to produce meaningful information
Authentication
verifying that something is correct
Range Checks
checks that data is between two endpoints, a minimum and a maximum value
Presence Checks
checks that something has been entered
Lookup Table
reduces error, used in situations such as to select a title from a menu
Check Digit
checks if an error has occurred by doing some sort of mathematical function, normally with one or two digits
Length Check
restricts how many characters can be entered into a text box
Format Check
checks the format of something, e.g. that a postcode or vehicle registration number is inputted correctly
Double Entry
used in situations where the same piece of data needs to be entered twice, identically, eg when changing a password
Mutable
Data that can be changed
Assembler
a computer program that will take the mnemonics used in assembly language and covert them into machine code so they can be processed by the computer. This is done by converting one word assembly instructions into opcode, and allocating memory to variables, often resulting in an operand
Compiler
takes code written in high-level language and translates it into machine code all at once, before any execution takes place
Interpreter
takes code written in high-level language and translates it into machine code one line at a time
Translator
tool that translates source code into object code. There are three types: assemblers, compilers and interpreters
Opcode
an instruction like and or not
Source Code
code which you type
Object Code
code which is executed
Lexical Analysis
takes the sequence of characters you wrote and translates it into a series of tokens, removing any white space, allowing the computer to see the collection of typed words
Symbol Table Construction
created to store variable names and subroutines, checking that variables have been declared properly
Syntax Analysis
checks to ensure the code conforms to the rules of that particular language, eg for missing semi-colons
Semantic Analysis
checks to ensure the program makes sense, eg checking that variables have been given suitable types and have been declared before use
Code Generation
the tokens are translated into object code
Guido van Rossum
the man who invented Python in 1991, naming it after Monty Python’s Flying Circus
IDE
Integrated Development Environment
a piece of software designed to help programmers write, test and edit their code, including compiling tools that format and translate the language the code into a language the computer can understand
IDLE
Integrated Development and Learning Environment
simple IDEs designed for people who are learning to code, with a shell window and an editing window
Shell Window
part of an IDLE that shows the output of the program
Editor Window
part of an IDE and IDLE used for typing in, editing and saving your code
Auto-indentation
where the editor automatically indents lines that need to be indented, such as those ending in colons
Syntax Errors
An error that occurs when a command does not follow the expected syntax of the language, e.g., when something is spelled incorrectly
Logic Errors
An error that causes a program to output an incorrect answer (does not necessarily crash the program)
Upper Camel Case
UpperCamelCase
Lower Camel Case
lowerCamelCase
Snake Case
Snake_Case
Runtime/Execution Error
An error that only occurs when the program is running and is difficult to foresee before a program is compiled and run, such as when a program requests more memory when none is available, so the program crashes
Linking Errors
An error that occurs when a programmer calls a function within a program and the correct library has not been linked to that program, such as when the square root of a function is used and the library that calculates the square root has not been given to the program
Rounding Error
Rounding is when a number is approximated to nearest whole number/tenth/hundredth etc, such as if 3.45 rounded to the nearest whole number is 35, an error of +0.5
Truncation Error
Truncating is when a number is approximated to a whole number/tenth/hundredth etc, nearer zero, such as if 34.9 truncated to whole number is 34, an error of -0.9
Str
shortened version of string
Bool
shortened version of boolean
Casting
converting to a particular data type
Exponentiation
raising to a power in python
DIV
integer division or quotient, which returns the whole number part after the division
MOD
returns only the remainder after division
Rational Operators
needed to compare two values or expressions, eg, comparing answers from two different users
Index
automatically assigns a numerical value to each character’s position in a string
==
exactly equal to
!=
not equal to
<
less than
>
greater than
<=
less than or equal to
> =
greater than or equal to
String handling
using tools to process strings
String handling
using tools to process strings
Selection Block
part of programming giving all the options and outputs that should be given for each one
Indent
gap at the start of a line of code
Nesting
occurs when one programming construct is used within another, allowing simpler codes
Iteration
the process of repeating an instruction
For Loops
repeats instructions a certain number of times
Inner Loop
loop inside another loop
Outer Loop
loop containing other loops
Indefinite Loop
also known as a condition-controlled loop, a loop that continues until a specific condition is met or broken
Break
a command within a loop that gets the loop to stop
Alphanumeric Characters
letters and numbers
Brute Force Attack
where hackers have multiple guesses in quick succession at your password until they eventually guess it correctly
Cyphertext
text that has been encrypted and cannot be decrypted without a decryption key
Digital Footprint
the record that is kept of everything you have done online
Nonalphanumeric Data
characters such as punctuation marks
Password
used to prove a person’s identity to a computer system, thus allowing them access to relevant data. These should be easy for the user to remember, but hard for other people to guess, can be guessed using formula:
Attempts = Number of charactersPassword length
User Access Levels
allowing different users to have access to different data, such as giving some people Read Only access, or allowing some people to access more data than others
Compression
process that reduces a file’s size for efficient storage and transmission
MP3
uses lossy compression to reduce the size of an audio file by removing background noise and any sounds that would not be heard by the human ear from the track, meaning it is difficult to tell when listening that anything has changed
Arithmetic Operations
used to manipulate numbers
Boolean Operations
can be used to join conditional statements together to form ‘complex conditions’
Complex Conditions
created by boolean expressions, such as and, or, not or xor
Virus
programs that can replicated themselves sand be spread from one system to another by attaching themselves to host files, used to modify or corrupt information on a targeted computer system
Worms
self-replicating programs that identify vulnerabilities in operating systems and enable remote control of the infected computer
Spyware
installed by opening attachments or downloading infected software, used to collect stored data without the user’s knowledge
Trojan Horse
a program that appears to perform a useful function, but also provides a ‘backdoor’ that allows data to be stolen
Cyberattacks
attacks on computers or networks that use various types of malware
Malware
malicious software, a broad term used describe software used to disrupt computer operation
Backdoor
built into a computer program that allows someone to bypass any security to get into it
Key Loggers
a type of software that can be used ot track keystrokes and capture passwords, accout numbers, fraudulent use or people’s online activity
Adware
not dangerous in its own right, but may contain links to other malware, such as viruses and key loggers
Phishing
fruad where an internet user is tricked, often by e-mail, into revealing personal or confidential information, eg bank details which can be used fraudulently
Social Engineering
psychological manipulation of people into revealing personal of confidential information, eg bank details which can be used fraudulently
Spear Phishing
a type of phishing with a specific target, where the person doing it has gathered information about their target to effectively fool them
Blagging
the act of convincing someone that you are someone else to make them directly give away information such as passwords
The Scheme
the first part of the URL, either HTTP or HTTPS
Subdomain
the second part of the URL, after the HTTP or HTTPS
Second Level Domain
the third part of the URL, before the .com
Top Level Domain
the fourth part of the URL, such as .com, .co.uk, .net, .gov
Sub Directory
the fifth part of the URL after the .com
Human Error
the biggest threat to any kind of cyber security
Shouldering
an attack designed to steal a victim’s password or other sensitive data, involving the attacker watching the user input information, for example, over their shoulder, and is often done at PIN machines
Name Generator Attack
attacks in which the victim is asked on an app or social media to put in personal details about themselves, often to produce a name, allowing attackers to find out key pieces of information about you to help them answer security questions that protect people’s accounts
Smishing
a form of phishing that is done through SMS
Acceptable Use Policy
a document that stipulates what users of a network may or may not do with that network
Anti-Malware
software that detects and removes harmful software, such as viruses, from a computer
Disaster Recovery Policy
a document that describes how a company would aim to recover from catastrophic damage to hardware, software or data
Fraud
the crime in which you purposefully deceive someone for monetary gain
Penetration Testing
where a company’s system is attacked and the results are reported back to the company
Cookie
a text file stored on your computer that contains details about a website that you have visited
Parity Checking
the most straightforward method of detecting errors, using a parity bit
Signature
all viruses have a unique signature that anti-virus software scans for
Anti-Virus
a program that can be loaded into memory when the computer is running that monitors activity on a computer system for the signs of virus infection that scans for a virus’s signature
Firewall
a security system that controls incoming and outgoing network traffic, that analyses packets of data to determine whether they should be allowed through or not, its function is to monitor where data has come from and where it is going and to determine if this communication is allowed by checking a list of pre-determined rules, not to stop viruses
SQL Injection
a technique where malicious user can inject SQL commands into SQL statement, via web page input, which can alter SQL statements and compromise the security of information held in a database
SQL
Structured Query Language
a set of commands that allow you to get information
DoS Attack
Denial of Service Attack, attempt to make your website and servers unavailable to legitimate users by swamping a system with fake requests, usually in an attempt to exhaust server resources, not to break system security, involving a single internet connection
Two’s Complement
an operation done on binary numbers, to turn them into the inverse i.e. turning a positive sign to negative
Radix Complement
methods of manipulating binary numbers, e.g. two’s complement
Hashing
performing an algorithm on a password which allows entered passwords to be checked, without allowing the actual password to be viewed
Archive
long-term storage of files no longer in use
FTP
File Transfer Protocol
used for uploading files
