Computer Science Flashcards
Paper 1 and 2
comp 1.5: what are the 3 types of system software
utility/application software, device drivers, operating software
comp 1.5: what does the operating system do
a piece of software that controls system hardware, it has mangers for each piece of hardware
comp 1.5: name all of the managers used by the operating system
memory manager, user manager, process manager, file manager
comp 1.5: what is a CLI
it is a command line interface
comp 1.5: what is a GUI
it is a graphical user interface
comp 1.5 what is a WIMP
stands for Windows Icons Mice and pull down menus, it is a system of software features designed to simplify system operation for the user
comp 1.5: name 4 types of utility software
defragmentation, encryption, compression, backup
comp 1.5: what is a single user OS
it is an operating system interned to only have a single user at a time, although more than one user can use the OS at different times, the user manager keeps track of this
comp 1.4: what is social engineering
someone being influenced into giving away info that could grant access to accounts
comp 1.4: what is an insider attack
it is an attack by someone on the inside where the give away vunerable info
comp 1.4: what is an active attack
using a technical method, such as malware or other to compromise a networks security
comp 1.4: what is a passive attack
this is an attack where attackers eavesdrop by ‘sniffing’ data packets
comp 1.4: what is a penetration test
this is where an organization performs a controlled attack on itself to identify its weak spots, this can be performed by ‘ethical hackers’
comp 1.4: name all of the types of malware
viruses - program in a program that spread
worms - code that spreads across a network without a host
trojan hoarse - pretends to be a program its not
ransomware - encrypts data on system, only decrypts when money is sent
spyware - tracks activity and gathers info
rootkit - modifies OS so antivirus does not work
backdoor - opens access to a computer that another malware takes advantage of
comp 1.4: what are and what do firewalls do
they are either hardware or software that ‘sits’ between the user and the internet that filter packets
comp 1.4: what are the 4 types of active attacks
brute force - tries many combos of numbers and letters to find a password, this is slow
dictionary - tries many common passwords
DoS - denial of service attack, floods a server with many usless requests, can be blocked by a firewall blocking a certain ip,
DDoS - distributed denial of service attack, used to unban an ip, requests are sent from a botnet
comp 1.4: what methods do firewalls use to filter packets
ip filtering - insert here
packet filtering - inspects data packets to see whether they meet a certain criteria
port blocking - blocks certain ports that can be used by hackers to gain access, such as port 22
what is a protocol
a set of rules
comp 1.4 what are the 4 methods of data interception
MITM - a man in the middle attack intercepts data by intercepting the users connection to the internet and viewing network traffic
insider attack
packet sniffing - a hacker intercepting data transfered across a network
SQL - structured query language, this is an attack where lines of code are inserted into a field in the website/other
comp 1.4: what are botnets
they are many machines infected with malware that can be used for DDoS attacks
comp 1.3: what is a switch in networks
it is a device that connects serval devices to make a wired network
comp 1.3: what is a network layer
they break up the sending of packets into different components, each component handles a different part of the communication(TCP/IP model)
comp 1.3: what is a NIC
a network interface controller is a device that provides connection between a device and the network
comp 1.3: what is a router
this is a piece of hardware that connects networks together
comp 1.3: what is a wireless access point
a piece of hardware which connects to a switch and allows WiFi devices to connect to the network
comp 1.3: what is a twister pair cable
ethernet cable, made of eight wires twister into pairs to reduce interference
comp 1.3: what is a LAN
local area network
comp 1.3: what is a client server model
the server is in control of the network, the client askes and it gives a response
comp 1.3: what is a WAN
wide area network
comp 1.3: what is a pier to pier (P2P) server model
this relies on each user to make sure they stay connected to the server, each pier can act as a client to the server
comp 1.3: what is the process of a client server model
first the client asks the server then the porosesses the request and then responds.
comp 1.3: what are the advantages of the pier to pier server model
cheaper, more robust, and it commonly used for streaming
comp 1.3: how does the internet work
the router provides the internet connection, it connects to a ISP (internet service provider) which then connects to a DNS (domain name service) which is the backbone of the internet
comp 1.3: what is the star network topology
all clients are connected to the central switch or server. if one client falls off all of them don’t, often used for LAN
comp 1.3: what is the mesh network topology
no central server which can fail, all of the computers are connected to all of the rest, can be very expensive if its wired, no one point of failure
comp 1.3: what is a partial mesh network topology
the same as a mesh network topology but not all of the computers are connected to all of the others
comp 1.3: what is WIFI
it is a set of protocolos that enables devices to communicate across radiowaves, there are different standards of wifi that opperate ove different frequencies and speeds, its official name is IEEE 802.11x
comp 1.3: what is WEP
wired equivalent protection is the weakest protection and is protected by one password
comp 1.3: what is WPA protection
WIFI protected access is better than WEP, it uses one password and encryption
comp 1.3: what is WPA2 protection
WIFI protected access v2 is better WPA bc it uses better encryption
comp 1.3: what is the IP
internet protocol, defines how packages should be transmitted over a wireless network, an IP header is attatched to the data to store the sourse and destination
comp 1.3: what is the ethernet protocol
this is a protocol that defines how data should be transmitted over a cable
comp 1.3: what is the TCP
transport control protocol, this splits data into small packets each with a header that defines the destination and how it reaches there
comp 1.3: what is the cloud
these are large datacentres
comp 1.3: what is a mac address
every network interface controller is has a media access control address that is globally unique and allows data to be sent to individual users
comp 1.3: what is a public ip address
routers that connect to WAN have a public ip so devices on the WAN can send data to devices on the LAN
comp 1.3: what is HTTP
hypertext transfer protocol is a protocol that determines how data is transferred between browser and web server
comp 1.3: what is a private ip address
a private ip adress is the IP for devices on a LAN to sue on that LAN
comp 1.3: what is FTP
file transfer protocol determines how binary data and text data are requested and sent to the client from the server
comp 1.3: what is HTTPS
HTTPS is secure HTTP that uses SSL (secure socket layer) in order to encrypt the data
comp 1.3: what is SMTP
simple mail transfer protocol determine how email data is sent from clients to servers
comp 1.3: what is POP
post office protocol is a protocol that determines how emails are retrieved from servers:
emails not in sync with the server
inbox is not kept consistern between devices
comp 1.3: what is IMAP
internet message access protocol is a protocol that determines how emails are retrieved from servers, it allows emails to be kept in sync, the inbox is consistent between devices
comp 2.1: what is decomposition
breaking the problem down into smaller parts to simplify it, the smaller problems can be called sub-problems
comp 2.1: what is a structure diagram
they are used to represent decomposition, they are divided into nodes, the smallest node contains one task
comp 2.1: what is algorithmic thinking
this is a way of finding a solution by finding the individual steps needed
comp 2.1: what is abstraction
where you remove the unnecessary details from a problem
comp 2.1: what is a linear search
this searches through a dataset and matches the first letter and then the next and the next until it finds a match
comp 2.1: what is a binary search
finds a midpoint in the data sees if what you want is higher or lower and then half again until it finds a match, only works in an ordered list
comp 2.1: what is a bubble sort
a bubble sort is a sort that orders a list by letting the things floaty to the top
comp 2.1: what is a merge sort
a merge sort idk look it up
Comp 1.1: what is the PC and what does it do
The program counter is the part of the CPU that holds the address of the next instruction
Comp 1.1: what is the MAR
The memory address register is the part of the CPU that stores the memory address of where details to be stored of fetched
Comp 1.1: what is the MDR
The memory data register is the part of the CPU that holds data fetched from or to be stored to main memory
Comp 1.1: what is the ACC
The accumulator hoods the results of calculations
Comp 1.1: what is the ALU
The algorithmic logic unit performs calculations
Comp 1.1: what is the control unit
The control unit decodes instructions and signals to control how data moves around the CPU
Comp 1.1: what does the cache do
Stores commonly used instructions so they are faster to execute
Comp 1.1: what do registers do
Registers store small amounts of data needed for processing, they are very fast
Comp 1.1: what are the 4 types of register in the CPU
MAR, MDR, PC, ACC
Comp 1.1: what is primary memory
RAM
Comp 1.1: what is BIOS and what does it stand for
Basic Input/Output System
Comp 1.2: what does the rom do
Read only memory, this helps yo wake up the computer and performs the post cycle, it helps to wake up the computer
Comp 1.2: what is virtual memory
When to computer runs out of primary storage it can make up for this with secondary storage
Comp 1.2: what are the 3 types of secondary storage
Magnetic, optical, solid state