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136 Cards in this Set
- Front
- Back
How are data and instructions represented |
binary |
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how many bits are in a byte |
8 |
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how many bytes are in a kilobyte |
1000 |
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How many bytes make a megabyte |
1000 |
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how many megabytes make a gigabyte |
1000 |
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how many gigabytes are in a twrabyte |
1000 |
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what is a character set |
a group of character codes |
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how to calculate image size |
width * height |
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how to calculate file size of an image |
image size * colour depth |
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how is sound recorded |
samples of the amplitude are taken at regular time intervals |
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what's the sampling rate symbol |
Hz |
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What is sampling rate |
number of samples per second |
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what is sample resolution |
number of bits per sample |
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how to calculate file size for sound file |
rate * resolution* seconds |
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how does lossy compression work |
deletes parts of the file permanently |
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how does lossless compression work |
represents the file in a more efficient way |
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what does compression do |
reduces file size |
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How does Run Length Encoding work |
Stores data in frequency value pairs |
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What is the symbol of the NOT date |
A line above the gate name |
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What is the symbol of the AND gate |
A dot |
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What is the symbol of the OR gate |
Addition symbol |
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What is the symbol of the XOR date |
A circle with a cross inside |
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What is this gate |
NOT gate |
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What is this gate |
AND gate |
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What is this gate |
OR gate |
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What is this gate |
XOR gate |
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What is an application software |
A software that carries out tasks useful for end users |
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What are types of system softwares |
Utility software, Operating systems |
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What does an Utility Software do |
Supports the running of the computer system |
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What dies an operating system do |
Manage hardware and other programs |
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What hardware does the operating system manage |
Processor, memory, input/ output devices |
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What software does the operating system manage |
Applications, Security |
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What is a high level language |
A more readable programming language |
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What is a Low level language |
A specific programming language |
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What are the advantages of a high level language |
More readable, portable |
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What is the disadvantage of a high level language |
Slower to execute |
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What is the advantage of a low level language |
Easier to optimise |
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What is the disadvantage of a low level language |
Specific to particular CPUs |
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What is the purpose of assemblers |
Turns assembly code into machine code |
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What is the purpose of compilers |
Turns High level language into Machine Code by producing an executable |
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What are the advantages of compilers |
No source code needed afterwards, fast to execute afterwards |
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What is the disadvantage of compilers |
Errors are only shown at the end |
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What is the purpose of interpreters |
Turns High level language into Machine Code by translating the instruction then executing it |
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What is the advantage of interpreters |
Errors discovered straight away |
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What is the disadvantage of interpreters |
Source code is needed to run |
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What is the purpose of the CPU |
Carries out program instructions using data |
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What is the purpose of the Arithmetic Logic Unit (ALU) in the CPU |
Carry out maths and logic equations |
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What is the purpose of the Control Unit in the CPU |
Decodes instructions |
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What is the purpose of the Cache in the CPU |
a small but fast memory that holds frequently accessed items |
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What is the purpose of the Clock in the CPU |
Produces a regular signal to synchronise components |
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What is the purpose of the Bus in the CPU |
Connect the components |
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What happens in the "fetch" part of the Fetch - Decode - Execute Cycle |
The next instruction is loaded from the main memory |
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What happens in the "Decode" part of the Fetch - Decode - Execute Cycle |
Instruction is interpreted by the Control Unit |
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What happens in the "Execute" part of the Fetch - Decode - Execute Cycle |
Instruction is carried out, results will be written to memory |
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How will the clock speed affect the performance of the computer system |
The rate of the Fetch - Decode - Execute cycle will increase if the clock speed is faster |
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How will the number of cores affect the performance of the computer system |
More instructions can be executed at the same time |
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How will the Cache size affect the performance of the computer system |
More regularly used items can be held which reduces the need to check the slower RAM |
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What is an Embedded system |
A computer inside other devices where they are simple and have one purpose only |
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What are the properties of RAM |
Main memory, Volatile, Holds open programs and data |
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What are the properties of ROM |
Main memory, Non-volatile, Contains the start up program, Loads the OS from storage to RAM |
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What are the properties of Secondary Storages |
Large, Non-volatile, long term storage programs and data |
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How does a magnetic secondary storage systemwork |
uses different levels of magnetic polarity to store data |
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What is an example of a magnetic secondary storage system |
Hard Disk Drive |
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What are the advantages of a magnetic secondary storage system |
Reliable, comes with large capacities |
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What are the disadvantages of a magnetic secondary storage system |
Not Durable, Noisy
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What is an example of a Solid State Secondary storage device |
Solid State Drive |
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How does A Solid State Secondary Storage Device works |
By using electronic circuitry |
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What are the advantages of a Solid State Secondary Storage device |
Fast read and write speeds, durable |
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What are the disadvantages of a Solid State Secondary Storage device |
Expensive per Gb |
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What is an example of an Optical Secondary Storage device |
DVD |
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How does the Optical Secondary Storage device work |
Using the reflection of light |
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What are the Advantages of an Optical Secondary Storage device |
Portable, Reliable |
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What are the Disdvantages of an Optical Secondary Storage device |
Not durable, Low capacity per disc |
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What is a Cloud storage device |
A storage device that stores data from a different location and can be accessed through the internet |
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How does the Cloud store data |
Using HDDs and/ or SSDs |
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What are the Advantages of the Cloud Storage device |
Versatile, easily scalable |
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What is the Disadvantage of an Optical Secondary Storage device |
Reliant on the cloud provider |
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What is PAN |
Personal Area Network which is used by a single person |
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What is LAN |
Local Area Network located in a small geographical area |
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What is WAN |
Wide Area Network which is owned by multiple entities |
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What are the advantages of a Wired Network |
Less prone to interference, Consistent Range which means that it wont be affected by obstacles, Greater Reliability and Bandwidth |
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What are the advantages of a Wireless Network |
Flexible, Easy to add new devices, Fewer wires to free up more space |
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How does Star Topology work |
Connecting a lot of devices to a central node |
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What is the Advantage of using Star Topology |
Easy to add new devices |
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What is the Disadvantage of using Star Topology |
Reliant on the central node |
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How does Bus Topology work |
Chaining all devices on a backbone cable |
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What is the Advantage of using Bus Topology |
Simple and cheap to set up |
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What is the Disadvantage of using Star Topology |
Low performance |
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What is a protocol |
A set of rules enabling devices to communicate with each other |
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How are protocols grouped together into layers |
By their functions |
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What are examples of protocols in the Application Layer |
HTTP, FTP, IMAP, SMTP |
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What does HTTP mean |
Hypertext Transfer Protocol |
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Some websites have HTTPS instead of HTTP, why |
The website is encrypted |
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What does the FTP (File Transfer Protocol) do |
Send files |
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What does the IMAP (Internet Message Access Protocol) do |
Receive Emails |
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What does the SMTP (Simple Mail Transfer Protocol) do |
Send Emails |
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What are examples of the Transport Layer |
TCP, UDP |
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What does the TCP (Transmission Control Protocol) do |
Splits data into packets and handles errors |
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What does UDP (User Datagram Protocol) do |
Splits data into packets but doesn't check if they arrive or not |
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What is an Advantage of the TCP and UDP |
TCP handles errors, UDP is quicker |
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What is an Disadvantage of the TCP and UDP |
TCP takes more time, UDP wont handle errors |
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What is an example of the Internet Layer |
IP |
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What does IP (Internet Protocol) do |
Assigns IP address to show where the device is located |
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What are the examples of the Link Layer |
WIFI, Bluetooth, Ethernet |
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What are the properties of WIFI |
Wireless, Used for WLANs |
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What are the properties of Bluetooth |
Wireless, For PANs |
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What are the properties of Ethernet |
Wired, For LANS primarily |
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What is Pharming |
Redirecting a site's traffic to a fake website |
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What should a desired password be consisted with |
At least 8 characters, Contains both Upper and Lower case letters, Contains Letters and Symbols |
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How to make sure that your password wont be recorded by hackers |
Do not save the password on untrusted devices, change your password once a month |
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What is Misconfigured Access Rights |
When a user can access something that they shouldn't |
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What is Removable Media |
USB sticks, discs |
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How can Removable Media be harmful |
The removable data can extract information or install malware |
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What does Unpatched or Outdated Software do to your device |
Hackers can exploit the bug before it's been patched |
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What is malware |
Malicious Software |
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What are the types of Malicious Software |
Virus, Trojan Horse, Spyware |
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What does a Virus do |
Replicates when the host runs |
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What does a Trojan Horse do |
A harmful software that appears harmless and useful |
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What does a spyware do |
Record your actions |
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What is an example of a Spyware |
A Keylogger |
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What is Blagging |
Trick someone by creating a fake scenario and use feelings to convince them to give out information |
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What is Phishing |
Getting fake information through messages |
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What is Shouldering |
Observing the entering of passwords through someone or cameras |
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What is Penetration Testing |
Simulating an attack to find issues |
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What is a White Box Penetration Testing |
Simulates an Internal attack |
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What is a Black Box Penetration Testing |
Simulates an External attack |
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What is CAPTCHA |
A test method to see if the user is human |
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What is Anti-Malware |
A software that relies on an updated database and Scans for unknown malware and Removes it |
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What is a Firewall |
A virtual wall that checks for packets and block them if they don't meet a rule |
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What is Mac Address Filtering |
Declining Mac Addresses which blocks the networked devices |
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What are examples of Biometrics |
Fingerprints, Iris Pattern, Facial Recognition, Voice Recognition |
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Why are Biometrics used |
Every person had unique biological characteristics |
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What is Encryption |
Scrambling data so that only people with a key can decrypt and understand the data |
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What is a Primary Key |
A special identifier in a record |
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What is a Foreign Key |
A primary key from another table |
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What does a relational database do |
Reduces redundancy and Inconsistancies |