Computer Science paper 1 all notes Flashcards
(175 cards)
1
Q
What is the definition of hardware?
A
Any physical component that makes up a computer, like the CPU, motherboard, monitor, and printer.
2
Q
What is the definition of software?
A
Any program or application that runs on a computer system.
3
Q
What is the purpose of the CPU?
A
The ‘brain’ of the computer that takes an input, processes data, and produces an output.
4
Q
What does the fetch-execute cycle involve?
A
Fetching, decoding, and executing instructions stored in memory.
5
Q
What occurs during the fetch phase of the fetch-execute cycle?
A
Copy memory address from the program counter to the MAR, get the instruction from MAR, and increment the program counter.
6
Q
What happens during the decode phase of the fetch-execute cycle?
A
The instruction in the MDR is loaded into the CU, decoded, and prepared for execution.
7
Q
What is the execution phase in the fetch-execute cycle?
A
The instruction is performed, which could involve various operations like calculations or data manipulation.
8
Q
What does Von Neumann architecture describe?
A
A system where the CPU runs programs stored in memory, consisting of instructions and data.
9
Q
What is the role of the Control Unit (CU) in the CPU?
A
Coordinates activities, decodes instructions, controls execution sequence, and manages timing.
10
Q
What is the function of the Arithmetic Logic Unit (ALU)?
A
Performs logic and arithmetic calculations.
11
Q
What is cache memory?
A
Very small, fast access memory for frequently used instructions and data.
12
Q
What are registers in the CPU?
A
Small bits of fast memory dedicated to specific functions within the CPU.
13
Q
What does the Memory Address Register (MAR) do?
A
Holds the address of the data to be fetched or stored.
14
Q
What is the function of the Memory Data Register (MDR)?
A
Holds the data or instruction that has been fetched from or is to be written to memory.
15
Q
What does the Program Counter (PC) do?
A
Holds the memory address of the next instruction and increments as the fetch-decode cycle runs.
16
Q
What is the purpose of the Accumulator?
A
Holds the results of calculations performed in the ALU.
17
Q
What factors affect CPU performance?
A
Clock speed, cache size, and number of cores.
18
Q
What is clock speed measured in?
A
Gigahertz (GHz), which is 1 billion cycles per second.
19
Q
What is the effect of increasing clock speed on CPU performance?
A
More tasks can be processed every second, increasing performance.
20
Q
What is overclocking?
A
Increasing the clock speed beyond the factory setup, which can potentially damage the CPU.
21
Q
How does cache size affect CPU performance?
A
A larger cache speeds up processing and CPU performance.
22
Q
What are cores in a CPU?
A
Complete processing units with their own ALU, CU, and registers.
23
Q
True or False: Doubling the number of cores will always double the speed of the processor.
A
False.
24
Q
What are embedded systems?
A
A CPU or computer with a specific, dedicated function within a larger system.
25
List three examples of embedded systems.
* Coffee maker
* GPS system
* Traffic lights
26
What are characteristics of embedded systems?
* Reliable
* Limited operating system
* Simple user interface
* Power efficient
* Housed within a larger unit
27
What are the two types of primary storage?
* RAM (random access memory)
* ROM (read only memory)
28
What is the purpose of RAM?
Holds the instructions and data currently in use by the CPU.
29
What is the primary characteristic of ROM?
Non-volatile memory that retains data when power is lost.
30
What is virtual memory?
Part of the hard drive used as temporary RAM when RAM is full.
31
What is the downside of using virtual memory?
It is slower than RAM due to hard drive access times.
32
What is the need for secondary storage?
To store files when the computer is off, as RAM is volatile and ROM is read-only.
33
What are common types of secondary storage?
* Optical storage
* Magnetic storage
* Solid state storage
34
What is the capacity range for hard disk drives?
2-8 TB.
35
What is a key advantage of solid state drives (SSDs)?
Faster read and write speeds due to no moving parts.
36
What is the primary disadvantage of SSDs compared to HDDs?
Higher cost per GB.
37
What is the primary use for USB sticks?
Transporting files.
38
What is the capacity of a standard CD?
Less than 1 GB.
39
What is the primary use of Blu-ray discs?
Storing movies and games.
40
What is the primary characteristic of DAT tapes?
Very large capacity, typically between 1-5 TB.
41
What is the speed characteristic of DVDs?
Faster than CDs but slower than Blu-rays.
42
What is the primary disadvantage of CD compared to Blu-ray?
Slower than Blu-ray.
43
What is the portability of CD?
Easy to carry in a large pocket or bag.
44
What affects the durability of CDs?
Quality of storage and exposure to sunlight.
45
What is the general lifespan of a CD?
10-25 years.
46
What is the cost comparison between CD and Blu-ray?
A bit more than CD but much cheaper than Blu-ray.
47
What are common uses for CDs?
Backup device, distribution of software, games, and storage of movies.
48
List the units of data storage.
* bit
* nibble
* byte
* kilobyte
* megabyte
* gigabyte
* terabyte
* petabyte
49
Why must data be stored in binary format?
Computers are made up of transistors that have two states: on or off.
50
How many different values can be stored in x bits?
2^number of bits.
51
What is the most significant bit?
The largest bit, i.e., the one in the place of 128.
52
What is the least significant bit?
The smallest bit, i.e., the one in the place of 1.
53
Describe the process of converting denary to binary.
Subtract the largest number from your original number, put a 1 in that column, repeat for others and put 0s in remaining columns.
54
How do you convert binary to denary?
Add up all the denary numbers that have a 1 below them.
55
What is the method for converting binary to hex?
Split the byte into two nibbles and add the column headings of the columns with a one in them.
56
What does hexadecimal 10 equal in decimal?
A.
57
What is an overflow error?
It occurs when the result of binary addition exceeds the available bits.
58
What happens during a left binary shift?
It multiplies the number by 2^number_of_times_shifted.
59
What is the effect of a right binary shift?
It divides the number by 2^number_of_times_shifted.
60
How many characters can be stored in a number of bits?
2^number of bits.
61
What are the two main character sets?
* ASCII
* Unicode
62
What is the limitation of ASCII?
It only represents basic characters needed for English.
63
How many characters can Extended ASCII represent?
256 unique characters.
64
What is the benefit of ASCII?
It uses less space than Unicode.
65
What is Unicode?
A character set that can represent characters from all major languages.
66
What is the maximum number of characters Unicode can represent?
65,536 characters.
67
What is image representation based on?
A series of pixels, stored in binary.
68
What is a bitmap image?
An image made up of squares called pixels.
69
What is a vector image?
An image created from mathematical expressions and points.
70
How is image file size calculated?
Height (pixels) x Width (pixels) x Colour depth.
71
What does resolution refer to in images?
The total amount of pixels that make up a bitmap image.
72
What is colour depth?
The number of bits stored per pixel in a bitmap image.
73
What is metadata?
Data about data, additional information stored with the image.
74
What is analogue to digital conversion (A2D)?
The process of converting analogue sound waves to digital form.
75
What factors affect sound file size?
Sample rate, duration, and bit depth.
76
What is the difference between lossy and lossless compression?
* Lossy: data is lost, irreversible
* Lossless: data is preserved, reversible.
77
What is the purpose of compression?
To reduce the size of the file for storage and transfer efficiency.
78
What is a LAN?
A local area network covering a small geographical area.
79
What is a WAN?
A wide area network that connects multiple LANs.
80
What is bandwidth?
The amount of data that can be sent and received successfully at any given time.
81
What can affect network performance?
* Number of users
* Transmission media
* Error rates
* Latency
82
What is the client-server model?
A server controls access and security to shared resources.
83
What is a peer-to-peer network?
A network where each computer is equal and manages its own files.
84
What is an advantage of a peer-to-peer model?
Easy to maintain, no dependency on a single computer.
85
What is a disadvantage of a peer-to-peer model?
The network is less secure.
86
What is a peer-to-peer network model?
A network model where each computer has equal responsibilities and can communicate directly with each other.
## Footnote
Most homes have a peer-to-peer network model.
87
What are the advantages of a peer-to-peer model?
* Very easy to maintain
* No dependency on a single computer
* Cheaper to set up
## Footnote
No expensive hardware is needed.
88
What are the disadvantages of a peer-to-peer model?
* Less secure
* Users manage their own backup and software updates
* Difficult to maintain a well-ordered file store
89
What is a client-server network model?
A network model where multiple clients request resources from a centralized server.
90
What are the advantages of a client-server model?
* Easier to manage security of files
* Easier to take backups of shared data
* Easier to install software updates centrally
91
What are the disadvantages of a client-server model?
* Can be expensive to set up and maintain
* Requires an IT specialist
* Server is a single point of failure
92
What is a Network Interface Card (NIC)?
A hardware component that allows a computer to connect to a network.
93
What does a Wireless Access Point (WAP) do?
Allows wireless devices to connect to a local area network without cables.
94
What is the range limitation of a Wireless Access Point?
The range is limited, often requiring multiple WAPs for complete coverage.
95
What is the difference between a switch and a hub?
A switch sends data to specific devices while a hub broadcasts data to all connected devices.
96
What is the primary function of a router?
Sends data packets between different networks and connects a WAN to multiple LANs.
97
What are the three main types of transmission media?
* UTP (Unshielded Twisted Pair)
* Coaxial
* Fibre Optic
98
What is the internet?
The most well-known Wide Area Network (WAN) that connects multiple networks globally.
99
What is the Domain Name System (DNS)?
A directory that translates human-readable domain names into numeric IP addresses.
100
What is the first step in how DNS works?
URL Entry: The user enters the URL of a website into the web browser.
101
What role do web servers play?
Store web pages and resources, handling client requests for those resources.
102
What is hosting?
The process of storing websites, files, and other content on servers accessible by users.
103
What are the advantages of cloud storage?
* Access any time
* Access anywhere
* Large storage capacity
* Low cost/free to set up
104
What is a star topology?
A network topology where all nodes are connected to a central switch.
105
What is a full mesh topology?
A topology where all nodes are interconnected, allowing multiple pathways for data.
106
What is Ethernet?
A wired networking standard using twisted pair cables to connect devices.
107
What is the primary advantage of Ethernet?
Fast data transfer speed and better physical security compared to wireless.
108
What is Wi-Fi?
A common standard for wireless networks that allows devices to connect without cables.
109
What is Bluetooth primarily used for?
Connecting personal devices such as headphones, mice, and keyboards.
110
What is encryption?
The method of scrambling data before transmission to protect it from unauthorized access.
111
What is symmetric encryption?
An encryption method using a single secret key for both encryption and decryption.
112
What is asymmetric encryption?
An encryption method that uses a pair of keys: a public key for encryption and a private key for decryption.
113
How is wireless data encrypted?
Using an SSID and password to create a master key for encrypting and decrypting data.
114
What key is used to decrypt a message sent by User A?
Private key
## Footnote
The private key is not shared with anyone else.
115
How is wireless data encrypted?
Using an SSID and password to create a master key
## Footnote
Devices connecting to the same network receive a copy of the master key.
116
What does the master key do in wireless encryption?
Encrypts plaintext into ciphertext before transmission
## Footnote
The same master key is used by the receiver to decrypt the ciphertext.
117
What is an IP address?
A unique identifier for devices communicating over the internet (WAN)
## Footnote
IP addresses can change and are dynamic.
118
How is IPv4 represented?
As 4 blocks of denary numbers between 0 and 255 separated by full stops
## Footnote
Each block is one byte (8 bits), totaling 32 bits.
119
What is the purpose of IPv6?
To provide more addresses as IPv4 is insufficient for the world's devices
## Footnote
IPv6 has 8 blocks of 4 hexadecimal digits, totaling 128 bits.
120
What is a MAC address?
A unique identifier for devices on a local area network (LAN)
## Footnote
MAC addresses are static and assigned during manufacturing.
121
What is the structure of a MAC address?
12 hexadecimal digits (48 bits) grouped in pairs
## Footnote
The first three pairs are the manufacturer ID, and the last three are the NIC serial number.
122
What is a computing standard?
A set of rules ensuring compatibility and interoperability between software and hardware
## Footnote
Standards allow different manufacturers to create compatible products.
123
Give an example of a computer standard.
HTML, Ethernet, USB, Wi-Fi
## Footnote
Each standard serves a specific purpose in computing.
124
What is a protocol in networking?
A set of rules that allows two devices to communicate
## Footnote
Examples include TCP/IP, HTTP, and FTP.
125
What does TCP do?
Ensures error-free communication between routers
## Footnote
It breaks data into packets and detects errors.
126
What is the role of IP in TCP/IP?
Delivers data to the right device on a WAN
## Footnote
It identifies device locations and routes packets accordingly.
127
What does HTTPS add to HTTP?
An added layer of security through encryption
## Footnote
It protects sensitive information during data transmission.
128
What is FTP used for?
Sending and receiving files between computers
## Footnote
It supports bulk transfers of large files efficiently.
129
What is the difference between POP and IMAP?
POP downloads emails and removes them from the server; IMAP retains copies on the server
## Footnote
IMAP allows access from multiple devices.
130
What is the purpose of dividing network functionality into layers?
To reduce complexity and make each layer manageable
## Footnote
Layers promote interoperability and simplify upgrades.
131
What is malware?
Malicious software designed to infect computers
## Footnote
It can include viruses, worms, trojans, and ransomware.
132
What is social engineering?
Exploiting human weaknesses to gain unauthorized access
## Footnote
Examples include phishing and pretexting.
133
What is a brute-force attack?
A trial-and-error method to decode encrypted data
## Footnote
It aims to discover passwords by exhaustive effort.
134
What is a denial of service attack?
Flooding a server with traffic to make it unavailable
## Footnote
A larger scale version is called a Distributed Denial of Service (DDoS) attack.
135
What is SQL injection?
Using malicious SQL code for unauthorized database access
## Footnote
It manipulates backend databases to access sensitive information.
136
What is the function of a firewall?
To monitor and control incoming and outgoing network traffic
## Footnote
It establishes barriers between trusted and untrusted networks.
137
What is anti-malware software?
Software that protects against various types of malware
## Footnote
It includes anti-virus, anti-spam, and anti-spyware solutions.
138
What is the purpose of user access levels?
To control user access to different data within a system
## Footnote
It ensures users have appropriate permissions based on their roles.
139
What is the purpose of operating systems?
To provide an interface between the user and hardware
## Footnote
They hide hardware complexities for user convenience.
140
What is a graphical user interface (GUI)?
An interface that uses visual elements for interaction
## Footnote
It is intuitive and user-friendly, designed for mouse interactions.
141
What is a command line interface?
An interface that requires users to input text commands
## Footnote
It is efficient but requires knowledge of commands.
142
What is a natural language interface?
A system that responds to questions spoken out loud
## Footnote
Examples include virtual assistants, search engines, and smart home devices.
143
What are the advantages of natural language interfaces?
Intuitive and can help people with disabilities
## Footnote
Not always reliable, but improving.
144
What is a menu interface?
Successive menus presented to the user with a single option at each stage
## Footnote
Examples include chip and pin machines and vending machines.
145
What are the characteristics of a command line interface (CLI)?
Requires text-based commands, less resource-heavy, more commands available
## Footnote
Helpful for automating tasks and faster than navigating menus.
146
Define memory management.
The process carried out by the operating system allocating main memory (RAM) between different programs
## Footnote
Manages RAM based on priority and fairness.
147
What is multitasking in computing?
Doing multiple tasks at once, managed by the OS to give the perception of simultaneous program use
## Footnote
The CPU executes one instruction at a time but can handle billions in a second.
148
What is peripheral management?
The process carried out by the OS managing how peripherals interact with software
## Footnote
Ensures sufficient operation and supports plug-and-play functionality.
149
What is a device driver?
A piece of software used to control a piece of hardware
## Footnote
OS-specific and often requires manufacturer updates for maximum capacity.
150
What is user management in computing?
The process enabling different users to log into a computer and customize their settings
## Footnote
Allows for different access rights on a network.
151
What does file management entail?
The process of creating, organizing, manipulating, and accessing files and folders
## Footnote
Includes capabilities like renaming, copying, moving, and deleting files.
152
What is utility software?
Software designed to help maintain, enhance, and troubleshoot a computer system
## Footnote
Not essential, but facilitates specific tasks.
153
What does encryption software do?
Uses algorithms to convert plain text into cypher text
## Footnote
Enhances security and keeps data safe.
154
What is defragmentation?
The process of reorganizing fragmented files to improve access speed
## Footnote
Solid state drives do not require defragmentation.
155
What is data compression?
A method to reduce file size for more disk space
## Footnote
Compression can be lossless or lossy.
156
What ethical issue does the digital divide represent?
Inequality in access to technology that hinders opportunities for education and employment
## Footnote
Affects disadvantaged groups.
157
What is algorithmic bias?
Unintentional unfair biases in decision-making algorithms
## Footnote
Can lead to discriminatory outcomes.
158
What does the Computer Misuse Act (1990) address?
Concerns the malicious use of computers, including unauthorized access and modification
## Footnote
Updated regularly to remain relevant.
159
What does the Data Protection Act 2018 protect?
Personal data from misuse, including name, address, date of birth, race, and religion
## Footnote
Most data holders must comply, with exceptions for police and intelligence services.
160
What is the role of software licenses?
Legal agreements that outline how software can be used
## Footnote
Includes open source and proprietary types.
161
Fill in the blank: A _______ is an external device that connects to a computer for input or output.
peripheral
162
True or False: The OS is responsible for copying programs and data from secondary to primary storage as needed.
True
163
What are the negative cultural impacts of remote working?
Social isolation, communication challenges, blurred work-life boundaries
## Footnote
Can lead to mismanagement of time and burnout.
164
What is a key environmental issue in computing?
Rapid disposal of devices leading to pollution
## Footnote
Includes contamination from hazardous materials in electronics.
165
What is a software licence?
A legal agreement that lays out rules for how software can and can’t be used
## Footnote
A software licence establishes the rights of all parties involved with the software.
166
What are the two main types of software licences?
Open source and proprietary
## Footnote
These types define how software can be used, modified, and distributed.
167
Why are software licenses important?
They establish the rights of all parties involved with the software
## Footnote
This includes the author, provider, and end users, defining their relationships and protections.
168
What is a key characteristic of open source software?
Access to source code to edit/change
## Footnote
Open source software is usually free and may allow editing and distribution.
169
List three advantages of open source software.
* Allows collaboration with others
* Less buggy versions may appear faster
* Generally free
170
List two disadvantages of open source software.
* Relies on support from other users
* Requires expert knowledge to edit code
171
What is a key characteristic of proprietary software?
Costs money
## Footnote
Proprietary software is produced by professional companies and is not normally distributed with source code.
172
List three advantages of proprietary software.
* Generally free customer support
* Created to professional standards
* Regular and official updates
173
List two disadvantages of proprietary software.
* Cost can be significant
* Limited expansion, only what is available
174
Fill in the blank: Open source software can be installed on _______ number of computers.
[any]
175
True or False: Proprietary software can usually be edited to meet the user's needs.
False
## Footnote
Proprietary software typically cannot be modified by the user.
