Paper 1 Flashcards
1
Q
What does the CPU stand for and what does it do?
A
Central processing unit, It processes data and instructions by carrying the FDE cycle.
2
Q
System Architecture
A
System Architecture
3
Q
What do cores do?
A
Cores allow data to be fetched and executed. More cores = more instructions executed at same time.
4
Q
What is the purpose of cache memory in a computer system?
A
Cache memory is a high-speed storage. It stores frequently accessed data and instructions to reduce the time needed to access them from main memory, improving processing speed.
5
Q
What is Clock-Speed?
A
When 1 instruction executed per cycle of clock, faster clock speed = more instruction can be executed per second.
6
Q
Name the registers and what do they do?
A
1-Accumulator=Stores results of calculations by ALU
2-MDR(Memory data register)=holds data and instructions being executed
3-MAR(Memory address register)=Holds memory adress about to be used by CPU
3-Program counter=Holds memory address of the next instruction to be executed
7
Q
What is the ALU?
A
ALU does calculations
8
Q
What is the control unit?
A
In control of CPU managing flow of data and FDE cycle.
9
Q
What does RAM do?
A
Stores currently used data and instructions
10
Q
True or False-RAM is Non-Volatile
A
False-RAM is volatile (wiped when machine turned off)
11
Q
What does ROM do?
A
Stores the ‘boot’ sequence to start device using BIOS
12
Q
True or False-ROM is Non-Volatile
A
True-ROM is volatile (data not wiped when device turned off)
13
Q
Explain virtual memory and what it is used for.
A
Used to store currently used data and instructions when RAM is full.
Secondary storage used to prevent crashing.
FDE takes longer as instructions need to be swapped out of virtual memory to RAM before being executed.
14
Q
System Software
A
System Software
15
Q
What is an Embedded system?
A
Computer built into larger devices dedicated yo carry out specific tasks. E.g Satnav in a car
16
Q
What is an operating system?
A
Software which is needed to run your device.
It controls and organises general operation of computer .
Manages hardware and run software.
17
Q
What are 5 functions of operating systems? (mumps)
A
Multitasking
User interface
Memory mngment
Peripheral mngment
Security(File + user mngment)
18
Q
What is multitaski ng?
A
allows more than one program to be open at one time.Does this by time slicing
19
Q
What is user interface?
A
What you see when you turn on device. (GUI) (CLI)
20
Q
What is memory management?
A
OS has to decide what goes where in memory and mange its use.
21
Q
What is peripheral management?
A
Allows users to manage devices used on a computer e,g keyboard
22
Q
What is File management?
A
Any editing to files e.g naming files deleting files
23
Q
What is user management?
A
Manages user accounts, passwords and profiles.
24
Q
What is utility software?
A
Software used to maintain and configure the computer.
25
What is defragmentation?
reorganizes sperated files back together on HDD resulting in faster access times.
26
What does security do?
Uses antivirus to check and remove known viruses
27
What is a full backup
A full backup is a complete copy of all data and files in a system at a specific point in time.
Purpose: Ensures that every file is backed up, making restoration straightforward.
Advantage: Simple and comprehensive.
Disadvantage: Takes up more storage space and time compared to other backup methods.
28
What id backup utilities
Scedulaes backups to computers so data can be recovered in case of loss.
29
What is a incremental backup?
An incremental backup saves only the data that has changed since the last backup (whether it was full or incremental).
Purpose: Reduces the amount of time and storage required for backups.
Advantage: Faster and uses less storage than a full backup.
Disadvantage: Restoring requires all incremental backups plus the last full backup.
30
What are device drivers?
Enables hardware and OS to communicate with each other. e.g wireless mouse
31
What is compression software?
Reduces size of files so they take up less disk space
32
What is encryption software?
scrambles data in files to stop third parties from accessing it
33
What is lossy compression?
Lossy compression is a data compression method that reduces file size by permanently removing some data, often deemed less important.
Common Uses: Images, audio, and video files (e.g., JPEG, MP3).
Advantages: Significantly reduces file size.
Disadvantages: Data loss is irreversible, and quality may be degraded compared to the original.
34
What is lossless compression?
Lossless compression is a data compression method that reduces file size without any loss of data.
How It Works: Encodes data more efficiently so that the original can be perfectly reconstructed.
Common Uses: Text, software files, and some image formats (e.g., PNG, ZIP).
Advantages: No loss of quality or information.
Disadvantages: Typically achieves less compression compared to lossy methods.
35
What is WAN?
Connects LANS in different geographical locations. e.g business with offices around world.
Organisations do not own all hardware
Internet is biggest example of WAN
36
What is LAN?
Covers a small geographical area e.g school.
Organisations owns all hardware
37
Networks
Networks
38
What is a network?
When 1 or more devices connected together to share information and resources
39
What are the benefits of networks?
.File sharing is easier
.Share hardware e.g printers
.Share internet connections
.Install and update software centrally
.User accounts stored centrally so you can log into any machine
40
What factors effect the network performance?
.Bandwidth=amount of data that can be transferred at one time
.Too many users
.Wired vs wireless (on next flashcard)
41
Compare wireless and wired connections.
Wired connections faster and reliable. Wireless depends on signal quality so is affected by range of device and interference by walls or other devices.
Wired are less portable but wireless is portable.
42
What hardware is needed for a network?
1)Network interface controller
2)Switch
3)Router
4)Transmission media
5)Wireless access point (WAP)
43
What is a network interface controller?
Internal hardware which allows device to connect to network
44
What is a switch?
Connect devices on a LAN and receive and transmit data on a MAC address,
45
What is a router?
Transmit data between networks
46
What is transmission media?
.Ethernet=standard wired method of connecting a network using twisted pair of copper cables
.Fibre Optic-= made of glass and transmits data as light. Fast data transmissions but expensive
47
What is WAP?
Allows devices to connect wirelessly using wifi
48
What is a Client server?
Managed by a server with connected devices called clients. Client sends request to server and server responds.
49
What is WIFI?
Protocol which uses 2 radio frequency bands ADD DETAIL LATER
50
What are benefits of client server?
.Easy to manage centrally e.g. manage files, take back-ups, install and update software
.Easy to manage network security e.g. anti-malware and user access levels
51
What is peer to peer?
All computer has equal status no computer has control over network. Each machine known as a peer and stores own files.
52
What are problems of client server?
.Expensive to set-up
.Needs IT specialists to maintain
.If the server goes down all clients lose access to their work
.The server main struggle with performance if too many clients make requests at once
53
What are benefits of peer to peer?
.Easy to maintain – you don’t need specific expertise or expensive hardware
54
What are problems of peer to peer?
.No centralised management – devices need to individually updated and software installed.
.Data may be lost if it’s held one machine that fails
55
What is star topology?
all devices connected to a central switch or server.
56
What are benefits of star topology?
.If a device fails the others are not affected
.simple to add more devices
.Few data collisions due to setup
57
Storage
Storage
58
What are problems of star topology?
.Wired star networks can be expensive as every device needs a cable
.If there is a problem with the switch or server the whole network is affected
59
What is Mesh topology?
A topology where devices are directly or indirectly connected to each other without the need for a central server, data travels along fastest route form one device to another.
60
What are benefits of mesh topology?
There is no single point where the network can fail – if a device fails the data is sent along a different route
61
What are problems of mesh topology?
If wired can be expensive however with more people opting for wireless technology this is a practical option
62
Describe optical
Stores data on disks which can be read by lasers. Very portable and cheap however can be scratched easily
63
What is secondary storage needed for and is it volatile or non-volatile?
Is needed to store programs permanently when not in use. It is non- volatile
64
Describe Magnetic
High capacity storage using magnetic tech including HDD. Usually large and less portable due to moving parts. cheap per GB and high capacity
65
Describe solid state
stores data electronically on chips without moving parts therefore is more durable. smaller and more portable e,g SSD. Faster read/write times but are more expensive per GB
66
Internet
Internet
67
What is a DNS?
Domain name service so the user doesn't have to remember IP address.
68
What happens when a user types a URL in a web browser?
The computer will query the a DNS server.
The DNS server has a list of all domain names and their IP addresses.
DNS server sends back the corresponding IP address and the web browser sends request to IP address for the website.
69
What is hosting?
When your website is placed on a web server.
70
What is the cloud?
Something that stores files and applications using the internet
71
What are pros of the cloud?
1)Files can be easily accessed from any connected device
2) Easy to increase storage available
3)No need to buy expensive hardware
72
What are the cons of the cloud?
1)Internet connection needed for access
2)Data more vulnerable to hackers
3)Fees for subscription
4)Dependent on host for installing security and backups
73
What is web servers and clients?
Websites hosted on web servers. Web browser are client program that send request to the web server hosting the wanted website.
74
What is Bandwidth?
Measurement for amount of data which can be transferred over connection at one time. Measured per second.
75
What is Encryption?
Data that is coded so that is it is intercepted it can only be decrypted (become understandable) with the correct 'key'
76
What is an IP address?
A set of numbers needed to identify a computer.
77
What is an MAC address?
Address assigned to devices for communications in a network
78
What is a virtual network?
A virtual network is software based. It is created by partitioning off a physical networks bandwidth to form a separate network
79
Compression
Compression
79
Why is data compression needed?
.Take up less secondary storage space on a device
.use less bandwidth when downloading files on the internet
.Allows web-pages to open more quickly in browsers
80
What is lossy compression? and what are problems and benefits?
Lossy greatly reduces files size and is commonly used so can be read by lots of software.
However it loses data so original data is gone and can;t be used on text as they need to retail all their data.
81
What is lossless compression and what are its problems and benefits?
Data is only removed temporally and original file can be restored. However only a small reduction on file size.
82
Network security threats
Network security threats
82
What is malware?
Malicious software designed to do harm which is installed on ones device without consent. e,g spyware
82
How do you prevent malware?
Use anti-malware software and firewalls
82
What is social engineering?
Using people to gain information in network. e.g phishing
83
How do you prevent social engineering?
Train users to recognize threats
84
How do you prevent brute-force attacks?
Have strong passwords and software the blocks attempts after getting the password wrong multiple times.
84
What is brute-force attacks?
An attack that uses software to crack passwords with trial and error
85
How do you prevent DDOS attacks?
Monitor for unusual activity
85
What is DDOS attacks?
an attack which overloads the web server with requests stopping other users from being able to access it.
86
What is data interception and theft?
unauthorized access of a system or data. Also known as hacking
87
How do you prevent Data interception and theft?
Penetration testing, Encryption, Physical security, Strong passwords
87
How do you prevent SQL injections?
Input validation – ensuring malicious code can not be entered.
87
What are SQL injections?
Used to access information in databases. When SQL is typed into input box to access sensitive information
88
What is the data protection act 2018?
law that protects and controls the use of personal data which is held about a person
89
What is the computer misuse act 1990?
Prevents illegal access to files such as hacking, cyber crime and writing/disturbing malware
90
What is the copy write designs and patents act 1988?
Protects assets and software created from others using them without permission/fee
90
What is an open source?
When users have the right to copy, modify and share the product-have access to source code.
Usually free and community of contributes with a range of expertise can contribute to the continues improvement of product
91
What is on the shelf?
Users are licensees and cannot copy or modify or share the product.
Not free and users rely on vendor to support and update product,
Vendor in complete charge of update cycle and developing new features.
92
Numbers
Numbers
92
Why is data represented in binary form?
.Computer work in binary as it is easy to show 2 states (on or off)
93
Convert this to Binary: 46
Convert this to denary: 00011001
.00101110
.25
93
Why do we use hex?
.Large binary numbers hard to remember
Programmers want something that is easily converted from binary but also easy to recognise
.Hex is less prone to error
93
93
Explain how to go from binary to hex by using :00011011
Split byte to nibble: 0001 1011
Convert to denary: 1 11
Convert to hex: 1B
A=10
B=11
C=12
D=13
E=14
F=15
94
State the rules of binary addition
1+1=10
1+0=1
1+1+1=11
95
How is SOUND represented?
Sound must be converted to digital to be stored as binary. This is called sampling
95
How is sound converted to binary?
The amplitude of the sound wave is measured at regular intervals and converted. The more frequent the measurement the higher the quality of the sound.
96
How are IMAGES represented?
Images are stored as pixels. The colour of each pixel is represented by a binary code. 1-bit can represent 2 colours – 0 for white and 1 for black. The more bits the more colours can be represented. This is called colour depth. Most devices use 24-bit colour depth 224
Total number of colours = 2n (where n = number of bits per pixel)
96
What is Metadata?
Information stored about the image such as file format, height, width, colour depth and resolution,
96
How are CHARACTERS represented?
Alphanumeric characters are used to make strings. Computers convert the characters to binary busing a character set. This includes all the keys on the keyboard (in whatever language) and emojis.
97
What is resolution?
The density of pixels in an image(DPI). The higher the resolution the better the quality of the images however the file size will be higher.
97
How many bits and characters does ASCII represent?
7-bit character set can represent 128 characters
97
How many bits and characters does Extended ASCII represent?
8-bit code allowing for 256 characters.
98
How many bits and characters does Unicode represent?
16 or 32-bit code which covers all major languages.
99
Describe IPv4
.In decimal
.made up of 4 numbers from 0-255
separated by full stops
100
Describe IPv6
In hex
made up of 8 sets
in hex
seperated by colons
101
Describe a MAC address
Made up of a set of 6 numbers
separated by colons
Can be a set of 8
102
What are the 3 main uses of utility?
Compression, Encryption, Defrag
103
Difference between internet and world wide web
Internet is collection of networks. WWW is web pages stores on servers
104
Why are star networks not the same as client server networks
A network topology (client server) describes how devices physically connected
A network model (star network) describes how data and resources are managed.
105
What is bitmap?
Bitmap image is made up of a grid of pixels and each pixel represents a specific color
124
