Paper 1 Flashcards
(81 cards)
1
Q
Embedded Systems (S)
A
Embedded Systems
- built inside a larger system
- usually dedicated systems
- single task, cheap, efficient, easier to design
- cheaper than providing a full personal computer system
- can be made much smaller than a personal computer
- allows for device to be automated / programmed
- specific, pre-defined function
- Do the same thing repeatedly
- Basic or no UI
- may respond to sensors
Examples
- Dishwasher
- MP3 player
- Washing machine
- Mobile phone
- Manufacturing equipment
- Tills
2
Q
CPU (S)
A
CPU (central processing unit)
- brain of computer
- process all data instructions
- power depends on, clock speed, cache, number of cores.
- installed on motherboard
3
Q
Control Unit (S)
A
Control Unit (CU)
- controls flow of data between registers in CPU
- controls flow of data in and out of CPU
- controls fetch-decode-execute by following fetch-execute cycle
4
Q
Arithmetic Logic Unit (ALU) (S)
A
Arithmetic Logic Unit (ALU)
- performs arithmetic and logic operations
- contains accumulator register
5
Q
Cache (S)
A
Cache
- very fast memory in the CPU, slower than registers but faster than RAM
- stores regularly used data and instructions, so it can be quickly accessed by CPU
- built into CPU so quicker accessed
- CPU checks cache first then RAM
- very low capacity and are expensive
Different levels Level One (L1) is quickest but has least capacity Level Three (L3) is slowest but has the most capacity
6
Q
Program Counter (H)
A
Program Counter (PC) - holds memory address of instruction for each cycle
7
Q
Accumulator (S)
A
Accumulator
- stores results of calculations in ALU
8
Q
Memory Address Register (MAR) (S)
A
MAR
- holds address of next instruction to be accessed
9
Q
Memory Data Register (MDR) (S)
A
MDR
- holds actual data or instruction, may have been fetched form memory or waiting to be written
10
Q
Fetch Decode Execute Cycle (S)
A
Fetch Instruction
- copy memory address from program counter to MAR. Copy instruction stored at address to MDR.
- Increment program counter
Decode Instruction
- Instruction in MDR is decoded by CU
Execute Instruction
- instruction is performed
11
Q
RAM (S)
A
RAM (high speed, volatile memory)
- random access memory, used as main memory
- volatile (temporary memory, require power to retain data)
- where all data, files and programs are stored while they are being used (data about programs currently in use)
- when computer boots, OS is copied from secondary storage to RAM
- when applications are opened, they are copied from secondary storage to RAM
- faster then secondary storage (HDD or SSD) so less time in ‘fetch’ stage of FDE cycle, but slower than cache
- More expensive per GB than HDD or SSD, this limits usage of RAM and the amount that can be installed
12
Q
Virtual Memory (S)
A
Virtual Memory
- secondary storage used as RAM
- when RAM is full, data is moved to secondary storage that hasn’t been recently used
- file allocated on secondary storage for memory
- to read data CPU transfers data back to RAM slower transfers on secondary storage then on RAM
13
Q
ROM (read only memory) (S)
A
ROM (read only memory)
- non - volatile (permanent memory), can only be read
- contains all instructions needed to boot up called BIOS (basic input output system)
- tells CPU to perform self checks and set up computer, test memory, hardware and OS are working.
- possible to ‘flash’ BIOS in ROM chip
14
Q
Clock Speed (S)
A
Clock Speed
- number of instructions per second (Hz)
- amount of fetch decode execute cycles per second
- can be overclocked, but can overheat, crash or cause permanent damage to system.
- faster clock speed more instructions per second
15
Q
Cache Size (S)
A
Cache Size
- larger cache, more space for frequently used instructions
- this means more storage for fast access, meaning faster fetching of instructions and so faster processing
- faster access to more data it needs to process
16
Q
Number of Cores (S)
A
Number of Cores
- more cores allow more instructions to be processed at the same time
- can carry more instructions out at once, more programs can run at the same time
17
Q
Character Sets (S)
A
- allow computers to understand letters, numbers and other characters
ASCII
- 8 bits long, 1 byte long (256 characters)
- extra 0 added to the end (right) to make 8bit (1 byte)
- One language (English alphabet, numbers, symbols and commands)
- letters are orders (A then B), symbols scattered in between
Unicode
- multiple bytes for each character
- covers all major languages
- first 256 characters identical to ASCII
18
Q
Storing Sound (S)
A
Storing Sound
- recorded as analogue (pieces of continually changing data)
- must be encoded into binary (analogue to digital converters), called sampling
- broken down into thousands of samples per second, stored as binary data
Sample rate - measured in Hz, amount of samples per second
more samples = more detail = clear sound = more space needed
Bit Depth
- bits available for each sample
- file picks up quitter sounds, closer quality to original
higher bit depth = higher quality = more space needed
Duration
- Higher duration = longer audio = more space needed
19
Q
Storing Images (S)
A
Storing Images
- Images stored as series of pixels in binary
- each pixel has specific colour, represented by a specific binary code
- contains metadata (structure of the file, size of grid, date etc)
- number of colours available related to number of bits the code has for each pixel, greater shades by increasing number of bits
- resolution, number of pixels
- higher resolution = more pixels = clearer image = more space needed
- Colour depths the number of bits used to sore the colour for each pixel
- Higher colour depth = more realistic colours = more space needed
20
Q
Lossless Compression (S)
A
Lossless Compression
- Compresses data files without losing any of the information
- reversible, original data can be restored
- Not all files can be compressed in this way
- used on text and software files
- only slight reduction in file size
21
Q
Lossy Compression (S)
A
Lossy Compression
- Does lose some of the information
- Used where this is acceptable (audio) (not text or software files)
- produces smaller files
- Poorer quality
- Commonly Used
- less bandwidth (download or upload)
- Greatly reduced file size
22
Q
Units of Data Storage (S)
A
Units of Data Storage
- Bit
- Nibble - 4 Bits
- Byte - 8 Bits
- Kilobyte - 1,000 Bytes
- Megabyte - 1,000 KB
- Gigabyte - 1,000 MB
- Terabyte - 1,000 GB
- Petabyte - 1,000 TB
23
Q
Binary (S)
A
Binary
- made up of 1s and 0s
- only two possibilities so this is a base two system
- Computer uses binary because the CPU contains transistors which are either on or off
24
Q
Hexadecimal (S)
A
Hexadecimal
- 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F
- 16 possibilities so this is a base 16 system
- Binary strings are long and hard to work with, hexadecimal is shorter and easier to work with
- easily converted to binary as there is 1 hex digit per nibble
- less prone to error
25
Choosing Storage Media (S)
Choosing Storage Media
Capacity - How much data the storage can hold
Speed - How quickly data can be written and read back
- some situations such as a live website will need data to be accessible quickly
- In other situations, such as backup, it is acceptable for the process to take longer
Portability
- How easy it is to move the storage media form one device to another
- size and compatibility of the media
Durability
- The length of the time the storage media is expected to last
- How easily damaged the storage media is
Reliability
- How like the storage media is to fail and how likely errors are to occur
Cost
- How expensive the storage media and any required hardware is
26
Secondary Storage (S)
Secondary Storage
- non-volatile (retains data without power)
- storage devices that are not constantly connected to the computer
- Storage devices not directly accessible by the systems CPU
- used to back up data stored in primary storage
- useful when there is a need for larger capacity
- where all data is stored when not currently in use
27
Optical Storage (S)
Optical Storage (CDs, DVDs)
- low capacity and slow read/write and poor reliability compared to flash storage devices
- Data is read and written using laser beams
- Inexpensive, reliable, robust, relatively large capacity
28
Magnetic Tapes (S)
Magnetic Tape
- much greater storage capacity than HDDs and low cost per GB
- often used by large organisation's to large amounts of data
- tape is read/written sequentially, from beginning to end or until stopped by computer means that tape is very slow when finding data stored on it but has fast read/write speeds once at correct place to begin
- reliable and cost effective
29
Solid State Storage (S)
Solid State Storage
- Data is stored within flash chips
- examples include USB drives and SSDs
- Flexible, faster access to data, can be used for portable devices, generally smaller in size, robust, easy to use
- no moving parts, significantly faster read/write speeds than HDDs, faster booting and opening times for programs and files
- shorter read/write life than HDDs
- silent compared to HDDs
30
Factors Which Affect Network Performance (S)
Bandwidth
- the amount of data that can be transmitted in a given time
- The larger the amount of available bandwidth, the more data can be transmitted in a period of time
- Bandwidth is shared too many devices can slow down the network, you can limit bandwidth for users
Type of Connection
- wired connections will be faster than wireless, doesn't depend on signal quality or range or interference
- choice of hardware other than cables and network topology
Interference
- walls and other radio signals can interfere with wireless networks, electrical cables can interfere with wired networks
Number of Devices
- there will be less bandwidth if more devices, less bandwidth available to each user
Type of media being accessed
- large files consume more bandwidth, like HD video will take longer to transfer
31
Protocols (S)
Protocols
- HTTP, Hyper Text Transfer Protocol - Used by web browsers to access websites and communicate with servers
- HTTPS, Hyper Text Transfer Protocol (secure) - More secure version of HTTP. Encrypts all data
- FTP, File Transfer Protocol - used to access, edit and move files between devices on a network
- SMTP - Simple Mail Transfer Protocol - send emails
- IMAP - Internet Message Access Protocol - Receive emails. Holds email until you actually delete it, you only download a copy
- POP3, Post Office Protocol version 3 - Receive emails. holds email until you download it, at which point it is deleted from the server
- DNS, Domain Name System - Converts names to IP Addresses
- IP, Internet Protocol - Addresses packets, directing packets to their destination across a network
- TCP, Transmission Control Protocol - Provides reliable transmission, provides rules for how devices connect to network, in charge of splitting data packets and reassembling them once they reach destination. responsible for checking data is correctly sent and delivered
32
The Internet (S)
The Internet - A worldwide collection of computer networks
Hosting - A service which allows you to publish a website to the internet, business uses its servers to store files of another organisation
DNS ( Domain Name System) - A system for converting host names and web addresses into IP addresses
Web Server - A server configured to host websites
Web Client - A client accessing websites, usually over The internet
33
MAC Address (S)
MAC Address
Media Access Control (MAC) - 48 or 64 bits Hexadecimal values
- mainly used by the Ethernet protocol on LANs. LAN switches read the MAC addresses and use them to direct data to the correct destination
34
IP Address (S)
IP Address
- Assigned manually or automatically before device can access the network
- IPv4 (32bits) IPv6 (128bits)
- IPv6 are split into 16bit chunks each one is given as a hexadecimal number
- IPv4 are spilt into 8 bit chunks each one given as a denary number
- 32 bits using 4 sets of decimal values from 0 - 255
- used to route traffic to the right network
35
Network Hardware (S)
Network Hardware
- Wireless Access Points, converts signals into radio waves allowing devices to connect wirelessly
- Switches Connects devices on a LAN together by transmitting data between devices with correct MAC address
- Routers transmit data between networks, connect networks together (Two LANS)
- NIC (Network Interface Card), A piece of hardware within a device which allows it to connect to the network
- Transmission Media, Connects the NIC to the router or switch. Could be: Wireless (radio waves), Ethernet (twisted pair coper cables), Fibre Optic
36
Ethernet (S)
Ethernet
- communication over a wired network
- uses MAC address
- uses error checking
- devices check that no other device is communicating over link before sending
37
Wi-Fi (S)
Wi-Fi
- Wireless connection that uses radio signals to transmit data through air
- Unsecured traffic can be intercepted easily
38
Bluetooth (S)
Bluetooth
- Wireless connection uses radio waves
- low bandwidth compared to Wi-Fi
- much shorter range than Wi-Fi
- Direct connection between two devices
- possible to send files but is slow
39
Cloud Computing (S)
Cloud Computing
- Software, processing or storage hosted in a remote location and accessed via the internet
- Easy and Quick to increase or decrease resources
- Maintenance by cloud provider
- Data stored on servers
- no upfront cost, pay for what they use each month
- Relies on having suitable internet connection
- Can access at any time
- No need to buy expensive hardware
- No IT staff
- Auto updates
40
LAN (Local Area Network) (S)
LAN (Local Area Network)
- small geographical area
- Usually contained within one building
- Equipment owned by organisation
- lower setup costs
- Faster speeds
- More control over security
- Sharing files is easier
- can share the same hardware
- install software updates on all computers at once
- User accounts stored centrally, log in from any device
- cheaply and easily
41
WAN (Wide Area Network) (S)
WAN (Wide Area Network)
- large geographical area
- connects buildings, towns or cities together
- Equipment owned by a telecommunications company
- Higher setup costs
- lower speeds
- Less control over security
42
Client-Server (S)
Client-Server
- all devices connected to server
- server stores account details
- clients access services from server
- Servers receive and process requests from clients
- if server fails, clients are unable to operate
- Easier to keep track of files, easier to perform back-ups, easier to update software, easier to manage network security, servers are very reliable and always on
- expensive and needs IT specialists
- server dependence
- server may become overloaded
43
Peer-to-Peer Networks (S)
Peer-to-Peer Networks
- all devices have equal status
- one device fails only the information on that device is inaccessible, rest carry on working
- easy to setup
- no central control, makes it harder to implement security and administration
- easy to maintain
- no centralised management (harder for backups and software updates)
- copying files between devices creates duplicate files so hard to keep track of.
- peer machines are less reliable
- prone to slow down when accessed
44
Layers (S)
Layers
- a layer is a group of protocols which have similar functions
- layers are self contained, don't need to know what is happening in other layers
- each layer serves the layer above it, does hidden work for the action on layer above
- in a network, data travels through layers where protocols add or remove extra information
- Layers allow one part of the protocol to be changed or rewritten without affecting the other parts
- Ensures that all different hardware and software can communicate (have standards, compatiable)
- Divides communication into smaller components, makes troubleshooting easier
- breaks down communication into manageable pieces for developers, layers can be changed without effecting others (self contained)
45
Star Network (S)
- all devices are connected to a central switch or server
- wired or wireless
Star Network (Advantages)
- If a single link breaks the network still stays active
- If one connection fails it does not affect the rest of the network
- Easy to add additional devices onto the network
- Fast because each device has its own connection to the switch / server
- There are few data collisions
Star Network (Disadvantages)
- Dependant on one central device
- If central device fails, the whole network fails
- Performance is also depended on one central device
- Number of devices is restricted by central device
46
Mesh Networks (S)
- all devices are connected to each other
- sending data along fastest route
Mesh Network (Advantages)
- If a link breaks another route is available
- The fastest route can be chosen
- Can be cheap if wireless
Mesh Network (Disadvantages)
- Expensive if wired
- More complicated to maintain
- Set up and maintenance can be costly
47
Forms Of Attack (S)
Forms Of Attack
Active – An attempt to modify or delete data, or to stop the network from operating correctly. someone attacks with malware or other planned attacks, best defences is fire wall, more easily detected
Passive – An attempt to find information about the network or retrieve information without changing anything, network monitoring software called packet sniffers hard to detect as hacker quietly listens, prevented by data encryption
Insider Attack – An attack by someone inside the organisation, exploits network access to steal information
48
Types of Malware (S)
Types of Malwares
Viruses - attach (by copying themselves) to certain files. Users spread them by copying infected files and activate by running infected files
Worms – Similar to viruses but self-replicate without users help, exploit weaknesses in network security
Trojans – Programs which pretend to be legitimate but are malware. Often disguised as email attachments. Cannot spread by themselves and so deceive a user into installing them
Spyware – Monitors user activities and send the information back to an attacker
Ransomware – Blackmails users into making a payment to an attacker. Some will only try to frighten users into paying, others will encrypt files
Scareware - tells user their computer is infected with loads of viruses to scare them into following malicious links or paying for non existing problems to be fixed
Rootkits - alter permissions, giving malware and hackers administrator level access to devices, opening backdoors holes in security that can be used for future accesses
49
Social Engineering (S)
Social Engineering – make mistake such as tricked into giving information. Phishing emails trick users into giving away information. Pretends to be a genuine message with a link to a website that looks like the real company
50
Brute Force (S)
Brute Force – Trial and Error. Tires all possible passwords until the correct one is found
51
Denial of Service (DOS) (S)
Denial of Service (DOS) – Overloads a computer or network with traffic by bombarding it with requests
52
Data Interception and Theft (S)
Data interception and Theft – Looking at data travelling over a network, often using a software called packet sniffer.
53
Structured query language (SQL) injection (S)
Structured query language (SQL) injection – affects websites that use a SQL database. SQL code is entered into a data input field on the website to look at or modify data stored in the database
54
Malware (S)
Malware – Malicious software designed to cause harm to a system or network. Users often ticked into running malware
55
Penetration Testing (S)
Penetration testing – The network is scanned for security weaknesses, vulnerabilities and poor configuration to find problems before an attacker can. Software if often used to automate this process. Allows organisations to find and fix threats before attackers can use them
56
User access levels (S)
User access levels – Controls which parts of a system users can access. Users should only be given access to part of the system they need. Limit the actions a user can take. Reduces the risk of both deliberate data theft, but also the damage that can be caused by social engineering attacks or malware
57
Secure Passwords (S)
Secure passwords – Passwords should not be easy to guess. Should be long and include numbers and symbols. Passwords should not be shared. Defence against brute force attacks, these take much longer with secure passwords
58
Anti Malware software (S)
Anti-Malware Software – Prevents malware from being installed and removes any that is installed. Includes anti-virus software, anti-phishing tools and anti-spyware software. Scans all files on computer and checking them against known list of malwares (isolate and destroy)
59
Firewalls (S)
Firewalls – Monitors traffic going into and out of a computer or network, and either allows or blocks it. Forms a barrier between a system and the attacker
60
Physical Security (S)
Physical Security – Controls access to servers, networking equipment and other important hardware. May take the form of security guards, locks, CCTV or swipe card
- protect from intentional or unintentional damage (fire, flood, theft, vandalism etc)
61
Operating Systems (S)
Operating Systems
- communicate with internal and external hardware, tells hardware what to do
- Allows computer to run other applications
- Controls the operations of a computer
- Provides interface between computer and user
- Hides complexities of the hardware from the user
- file management, disk management
- system security's and user accounts
- multi tasking, controls memory and CPU resources
62
Operating System Features (S)
Operating System Features
User Management
- Individual users can be created or deleted
- Allows more than one person to use a computer with their own files and settings
- Access levels for security
- A log is kept of files a user creates, accesses, edits and deletes
File Management
- All files are given a name
- Files are stored in folders
- Users can create, modify, move and delete files and folders
- Users can sort or search for files and folders
- Users can restore deleted files
- Users can set access rights to files
Multitasking
- Many tasks can be executed on a computer simultaneously
- OS has several processes running at the same time
- Processor is given small part of each task one after the other
- All tasks appear to be executing at the same time
- In reality, resources are shared between tasks
Peripheral Management
- Allows devices to communicate with the computer
- Data is transferred between devices and the processor
- Controlled Using Device Drivers:
- Contain instructions on how to control a device
- Each device has its own driver
- Any device can be used if a driver is available
- Drivers can be updated to give a better performance or fix bugs
63
Denary (Base-10) Standard Number System (S)
Denary (Base-10) Standard Number System
- ten numbers (0, 1, 2, 3, 4, 5, 6, 7, 8, 9)
- so base 10
64
Hard Disks (HDDs) (S)
Hard Disks (HDDs)
- magnetised metal disks that spin a thousand times a second
- data stored magnetically in small areas on disks circular tracks, moveable arm can access these areas and read/write
- long lasting and reliable although can be damaged by large impacts like being dropped
- Longer read/write life than SSDs
- Louder than SSDs
- Slower than SSDs
- Higher capacity than SSDs
65
BUS topology (S)
BUS topology
- All devices are arranged in a line, connected to a single backbone cable. Devices send data in both direction; This causes data collisions, which slows down the network
66
RING topology (S)
RING topology
- Data moves in one direction around the ring preventing collisions. But only one device can send data at a time and data passes through many devices before reaching destination
67
GUI (Graphical User Interface) (S)
GUI
- Uses windows icons Menus and Pointers (WIMP) to represent the interaction between the user and a computer
- User use a mouse to interact with features displayed on the monitor
- powerful and easy to use but require a lot of processing power
68
CLI (command line interface) (S)
CLI
- text based, less resource heavy then GUI
- aren't suitable for everyday users. But for advanced users they can be far more efficient and powerful than GUI, used to automate processes using scripts
69
Defragmentation Software (S)
Defragmentation
- files stored on hard disk in available spaces. Ideally, entire files should be stored together
- However, as files are moved, deleted and change size gaps begin to appear on disk, When writing files to the disk the OS splits files into smaller blocks to fill up the gaps
- Over time, the disk becomes more and more fragmented. This makes read/write slower as read/write head has to move back and forth across the disk
- Defragmentation software reorganises data on hard drive to put fragmented files back together, also moves files to collect all free space together, this helps prevent further fragmentation
- SSDs use flash storage with no moving parts, so fragmentation doesn't cause them any problems, can read and write just as fast no matter how they are arranged. In fact, defragmentation can shorten an SSDs life as they have limited read/writes
70
Compression Software (S)
Compression Software
- reduces size of files by permanently or temporarily removing data from them
- compressed files take up less disk space and are quicker to download
- compressed files need to be extracted before they can be used (.zip and .rar, lossless files)
71
Encryption Software (S)
Encryption Software
- Scrambles (encrypts) data to stop third-parties from accessing it
- intercepted or stolen data is still secure only intended readers of the data can unscramble and understand the data
- to decrypt a special 'key' is needed, A computer uses the key and a set of instructions to turn data back to original form
72
Ethical Issues (S)
Ethical Issues
- Ensuring public safety
- Cyber bullying and trolling
- Unequal access to materials
- The Digital Divide
- Virtual Currencies
- Social pressure to be online and keep up with the latest technology
- with smartphones work life can intrude into personal life
- face to face interaction is neglected
- Access to inappropriate / illegal content
- censorship and surveillance
- health problems (Repetitive strain injury, back problems (posture), Eyestrain)
73
Environmental Issues (S)
Environmental Issues (Positive)
- Industries such as manufacturing and agriculture are becoming more efficient
- Increase in renewable energy options
- Electronic communication reduces the need to travel
Environmental Issues (Negative)
- Extraction of natural resources depletes them
- Electronic components require precious metals
- Devices need large amounts of energy
- Large amounts of e-waste, people want the latest devices the old ones go to waste
74
Legal Issues (S)
Legal Issues
- Illegally sharing personal data
- stealing money or information
- Illegally copying and sharing films and music
- forcing information or blackmailing
- electronic spying
75
Cultural Issues (S)
Cultural Issues
- Automation can improve the production at the cost of jobs
- Technology gas allowed jobs to be moved abroad where costs are lower
- Not everyone is proficient with technology
- Not everyone can afford technology
- Internet access may be poor in rural areas
- people become attention-seeking and self-obsessed
- steaming through subscription services, people who's content is used feel like they don't get paid enough
- sharing economy (services that allow people to make money from things they already own such as Uber and Airbnb), these services are cheap but draw customers away from taxi firms and hotels more risky for customers (sharer may not know safety regulations or insurance policy wont cover theft)
76
Privacy Issues (S)
Privacy Issues
- Devices may be tracked
- Social media encourages people to post about themselves online
- Unwanted images and people may be put online
- Big data allows information from many different sources to be put together
- electronic information can be more easily copied
- Once information is online it is very difficult to remove it
- Not everyone is aware how to correctly use privacy settings
- companies may sell personal details
- users may accept privacy agreement without reading, even if they do they have no choice but to accept to use website
77
Data Protection Act (S)
Data Protection Act
- controls use of personal data
- before collecting data an organisation must register
with the government, saying what data they'll collect and how they will use it
- the act gives data subjects the right to see, amend and delete the personal data an organisation holds about them, but there are exceptions to this (an organisation don't have to disclose any data that could affect national security or outcome of a court case
- Act accountability, it is the responsibility of the organisation to make sure that they follow the rules - if not, they are large fines
Six Principles
- Data should be kept safe and secure
- Data must only be used in a fair, lawful and transparent way
- Data must only be used for the specified purpose
- Dara should be adequate, relevant and not excessive for the specified use
- Data must be accurate and kept up to data
- Data should not be kept longer than is necessary
Key roles
Information commissioner - has overall responsibility for enforcing the Data Protection Act
Data Controller - The person or organisation responsible for the data
Data Subject - The person who's data is being collected
78
Copyright Designs and Patents Act (S)
Copyrights, Designs and Patents Act
- Copy right covers written or recorded content, makes it illegal to share copyrighted files without the owners permission
- Patents covers new inventions - they protect ideas and concepts rather than actual content
79
Computer Misuse Act (S)
Computer Misuse Act
- introduced to stop hacking and cyber crime
Three new offences:
- Gaining unauthorised access to private network or device, e.g. through hacking
- Gaining unauthorised access to network or device in order to commit crime, (stealing data, destroying network, or to commit further crimes such as fraud and blackmailing)
- Unauthorised modification of computer material - deleting or changing files, also makes it illegal to make, supply or obtain malware
80
Open Source Software (S)
Open Source Software (Advantages)
- source code is freely available
- Free and available to use to anyone
- Can be modified to suit different needs (create own spin off software which can be shared under same licence and terms)
- Encourages collaboration
- Quick fix to issues
- strong online community, users actively help to improve software
- wide pool of collaborators can be more creative and innovative than the programmers of one company
- popular software is very reliable and secure - any problems are quickly solved by community
Open Source Software (Disadvantages)
- small projects may not get regular updates so could be buggy or have unpatched security holes
- for small projects there may be limed user documentation
- no warranties
- no customer support (although community forums make up for this)
- Companies using open source software to make custom software may not want competitors to see their source code, but they have no choice
81
Proprietary Software (S)
- only compiled code is released
- restrict the modification, copying and redistribution of software. usually paid for.
- Businesses often use property software as it tends to have better customer support
Proprietary Software (advantages)
- comes with warranties, documentation and customer support
- well tested and reliable as company's reputation depends on this. Fixes and updates come regularly
- usually cheaper for companies than developing own custom-built software
Proprietary Software (disadvantages)
- can be expensive
- may not fir a users needs, cant be modified
- may not maintain older software after warranties expire - want people to buy latest product
- Copyrighted by owner or company
