Component 1 Flashcards
(175 cards)
1
Q
What is software
A
Software is the non-physical layer where all the programs and applications run on.
2
Q
What are dedicated systems?
A
Computer systems which are created to carry out one funtion.
3
Q
What is hardware?
A
The hardware of a computer makes up the physical components such as the CPU, RAM, mouse etc.
4
Q
What is a computer?
A
A computer is a machine that processes data.
5
Q
What is an embedded system?
A
An embedded system is a computer which is built into other devices like microwaves. They are a type of dedicated system as they only carry out a few tasks.
6
Q
What are Pros of an embedded system?
A
1.More effecient
2.Cheaper
3.Easter to design
7
Q
What does the CPU do?
A
The CPU carries out all the instructions given to it by the system and handles all the data.
8
Q
What factors affect the power of a CPU?
A
Clock speed, number of cores and cache size
9
Q
What is Von Neumann architecture?
A
Von Neumann architecture is how modern computers work. It breaks down how a CPU runs programs and instructions using memory addresses.
10
Q
What are the 3 main componenets of a CPU?
A
The CU, ALU and Cache
11
Q
What does the CU do?
A
- The Control Unit Coordinates the processor
- Decodes instructions
- Runs the F - D - E cycle
12
Q
What does the ALU do
A
- Performs logic and arithmetic calculations.
13
Q
What is the Cache
A
It is a small block of very fast temporary memory
14
Q
What does the cache do?
A
It stores instructions or data most used or used recently.
15
Q
What the difference between L1 and L2 cache.
A
L1 cache is faster, and is in the CPU
L2 Cache is slower but has more storage.
16
Q
What are the 4 registers?
A
1.PC (Program Counter)
2.ACC (Accumulator)
3.MAR (Memory Adress Register)
4.MDR (Memory Data Register)
17
Q
What does the MAR do?
A
Holds the memory location of the data that needs to be accessed
18
Q
What does the MDR do?
A
Holds the data found at the address in the MAR, or holds data which is to be transferred to primary memory.
19
Q
what does the ACC do?
A
It is where the intermediate arithmetic and logic results are stored
20
Q
What does the PC do?
A
Contains the address of the next instruction to be executed
21
Q
What does the CIR do?
A
The CIR is a part of the CU and contains the current instruction during decoding or execution
22
Q
What happens during the Fetch cycle?
A
- Copy memory address form the PC to the MAR
- Copy Instructions from the MAR into MDR
- Increment PC to next instruction ready for next cycle
23
Q
What happens during the decode cycle?
A
1.Instructions in the MDR is decoded by the CPU
2.CPU might decide to load the next step from the MAR/MDR
24
Q
What happens during the execute cycle?
A
- Instructions are performed
- Could be reading, writing or halting a program
25
What is RAM
RAM is volatile memory and holds the data required for the program which is currently running
26
Why is RAM used instead of the hard drive
RAM is much faster
27
What is virtual memory?
Virtual memory is when the RAM is full, a part of secondary storage is used as extra storage for CPU
28
Why is virtual memory slower?
The data has to be written into secondary storage and back into RAM back and forth.
29
What is ROM
The ROM is a small chip on the motherboard that is non - volatile, which cannot be written to.
30
What does the ROM do?
The ROM stores the BIOS and stores all the instructions on how to start the computer. The CPU reads the ROM to perform checks on the system.
31
What factors affect the CPU performance?
Clock speed, No. Of cores and cache size.
32
What is OS for?
1. Allows for communication with internal and external hardware, vie device drivers.
2. Provides UI
3. Provides platform for applications to run
4. Allows the computer to multi-task, by controlling memory resources/CPU
5. Deals with file/disk management
6. Manages system security
33
What is a driver?
A piece of software, wich allows the OS to communcate with intenal hardware or peripherals.
34
What is the difference between GUI and command line interface?
1. GUI for normal users, it is visual
2. GUI is simpler for people
3. Command line is text based
4. Command line is less resource heavy, and can be used to automate processes using scripts.
35
What is secondary vs primary storage?
1. primary is the memory that the CPU can access very quickly, like RAM or caches, it is mostly volatile, but very fast.
2. Secondary is the memory where all data is stored when not in used. It is slower but non-volatile
36
What are different versions of secondary storage?
1. HDD - data is stored magnetically in small areas on the disk's tracks
2. SSD - have no moving parts, and use flash memory, so it is faster.
3. Optical discs
4. Magnetic tapes- for archiving as it has very low cost/GB
37
What are the pros of HDDs vs SSDs
1. SSDs are faster, don't need defragmenting, shock-proof and silent
2. HDDs are cheaper, longer read/write life and usually higher capacity
38
What are the 3 types of utility software?
1. Compression
2. Defragmentation
3. Encryption
39
What is Compression software?
1. reduces file size permanently/temporarily by removing data
2. Compression files take up less space and are quicker to donwload
3. .zip or .rar
4. Must be extracted before use
40
What is encryption software?
1. Encrypts data to stop third-parties from accessing it.
2. To decrypt, a special key is needed, which is then used to bring the data back.
41
What is defragmentation software?
1. Reorganises data on the hard drive, by putting fragmented files back together.
2. Moves the files to collect all free space together, to prevent further fragmentation.
42
Why do we need defragmentation software?
1. As files are moved, deleted or changed, small gaps appear on the disk
2. So when new files are written, the OS splits it into smaller blocks to fill the gaps. This causes fragmentation.
3. This fragmentation makes reading/writing slower.
43
What is an overflow error?
It is when a number has too many bits, resolve it by storing the extra bit elsewhere.
44
Which way is multiple and divide when shifting binary
Left is multiply, for every place shifted it doubles
Right is the opposite, so divide.
45
What is 1 Hexadecimal digit equal to?
1. Denary 1-15
2. A nibble
46
Why do programmers prefer Hex?
1. Simpler to remember large numbers
2. Less chance of input error
3. Easier to convert between binary and hex than binary and denary.
47
What is a character set?
1. collections of characters that a computer recognises from their binary representation.
48
What are 2 examples of character sets?
ASCII and Unicode
49
What is ASCII?
1. A character set in the english speaking world
2. Each ASCII character is given a 7 bit code, so it can represent 128 characters, including commands.
50
How do you work out the size of a text file?
File size = no. of bits per character x no. of characters.
51
What is colour depth?
The number of bits per pixel
52
How do you work out the number of colours in a bitmap?
No. of colours = 2^n
| Where n = no. of bits per pixel.
53
What colour depth do most devices use?
24 bit colour depth.
54
How do you find the file size of an image?
file size = image resolution x colour depth.
55
What is metadata?
The information stored in an image file, which helps the computer recreate the image on screen from binary data in each pixel.
Includes - file format, height, width, colour depth and resolution.
56
How is sound stored digitally?
1. Sound is recorded by an analogue signal microphone
2. This is converted into digital data by analogue to digital converters.
3. The process is called sampling.
57
How does sampling work?
1. We sample the amplitude of the wave at regular intervals, once the device has sampled it, the curve is recreated using blocks of data from where each sample was taken.
58
what is bit depth for sound?
Number of bits available for each sample
59
How do you calculate the size of a sound file?
file size = sample rate x bit depth x length(seconds)
60
What are the uses of compression?
1. Smaller files take up less space
2. Streaming and downloading from the internet is faster as it uses less bandwidth
3. Allows web pages to load quicker
4. Allows to send the same content with a smaller file size by email.
61
What are the 2 types of compression?
1.Lossy - Works by permanently remobing data from the file, this limits the number of bits the file needs, so reduces the size.
2.Lossless - makes the file smaller by temporarily removing data to store the file and restores it when opened.
62
What are the pros of lossy?
1. greatly reduces file size
2. takes up less bandwidth
3. Commonly used
63
What are the cons of lossy?
1. loses data
2. can't be used on text or software files
3. Worse quality than original, although usually unnoticable.
64
What are common lossy file types?
```
1.JPEG
2.AAC
3.MP3
```
65
What are the pros of lossless ?
1. data is only removed temporarily
2. Can be decompressed
3. Can be used on text and software.
66
What are the cons of lossless?
1. smaller reduction in file size.
67
What are examples of lossless file types?
```
1. FLAC
2. TIFF
3. PNG
```
68
What is a PAN?
A personal area network (PAN) connects electronic devices within a user's immediate area.
69
What is a LAN?
1.A Local Area Network, covers a small geographical area on a single site, and connects devices within it.
2.All the hardware for a LAN is owned by the organisation that uses it.
70
Why use a LAN?
1. Sharing files is easier
2. Share hardware
3. Internet can be shared
4. Can install updates all at once
5. Communication ischeap and easy
6. User accounts can be stored centrally, so anyone can login from anywhere in the LAN.
71
What is a WAN?
A Wide Area Network, it covers a large geographical area, connects LANs
72
Why do companies hire WAN infrastructure?
WANs are very expensive compared to LANs, so they hire dedicated Telecommunication companies
73
How are WANs connected?
1. fibre/copper telephone lines
2. satellites
3. radio
74
WHAT IS AN NIC
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1. A Nework Interface Controller, allows devices to connect to a network.
2. Usually built into the motherboard
3. Used for wired and wireless conections.
75
What is a switch?
A switch connects devices on a LAN, they receive data (in frames) from one device and transmit it to the device with the correct MAC address.
76
What is a router?
1. Routers transmit data between networks.
2. They direct packets to their destination on the internet
3. Used in homes/offices to connect the LAN to the internet
77
What are the 2 types of ethernet cables, and what is their structure?
1. CAT 5e and CAT 6
2. They are twisted pair cables, containing four paris of copper wires, twisted together to reduce interference.
78
What are coaxial cables made of?
A copper wire surrounded by a plastic layer of insulation and a metallic mesh, to provide shielding from interference.
79
What are fibre-optic
1.They transmit data as light
2.They are high performance, and don't suffer interference and can transmit over very large distances without loss of signal quality.
80
What is bluetooth?
1. direct connection between 2 devices so data can be shared
2. usually 10 metres
3. low bandwidth
81
What is Wi-Fi?
1. used by multiple devices to connect to a LAN
2. usually 40-100 metres range
3. Higher bandwidth
82
What is a WAP?
A Wireless Access Point is a switch but for wireless devices.
83
What are the different types of network attacks?
1.Passive attack
2.Active attack
3.Insider attack
4.Brute force attack
5.DoS attack
84
What is a passive attack?
| Explain what and how to defend
1.where someone monitors data travelling on a netwrok and intercepts sensitive info
2.They use netwrok-monitoring hardware and software like packet sniffers.
3.Hard to detect
4.Best defence is encryption
85
What is an active attack?
| Explain what and how to defend
1.When someone attacks a network with malware or other planned attacks
2.Use a firewall
86
What is an insider attack?
| Explain what and how to defend
1.Someone within an organisation uses network acces to steal info
2.Use passwords and user access levels
87
What is a brute force attack?
| Explain what and how to defend
1. Cracking passwords through trial and error.
2. Brute force attacks use automated software to produce likely password combos.
3. Locking accounts after a certain number of attempts and using strong passwords will reduce risk
88
What is a DoS attack?
| Explain what and how to defend
1. A denial of Service attack, where a hacker tries to stop users from accessing a part of network or website, by flooding network with useless traffic
89
YOKO GERI
SIDE THRUST KICK
90
What is malware?
Malicious software installed on someone's device without knowledge or consent
91
What can malware do?
1.Delete/modify files
2.scareware
3.lock files(ransomware)
4.Spyware
5.Rootkits altering permission
6.open backdoors.
92
What does clock speed mean?
1. number of instructions a single processor can carry out per second
93
What are cores?
A core is a part of the CPU which can process data independently of the rest, the more cores, the more instructions it can carry out at once
94
What are GPUs?
a GPU (Graphics Processing Unit) is a specialised piece of hardare which handles graphics and image processing, and relives the load on the CPU.
95
how do you convert hex into denary?
1. multiply the first digit by 16 then the next on by 1 and add them together
96
How do you convert binary into hex?
1. Split the binary number into nibbles
2. Draw a table with column labled 1248, for as many nibbles as there are
3. Fill the table with binary number
4. Sum the value of each nibble
5. Convert these sums into the hex version
6. Labosh
97
What is Unicode?
1. A character set which comes in several different forms and tries to cover every letter or symbol possible
2. It uses multiple bytes per character
98
What factors affect network speed?
1. Bandwidth - the more the better
2. Mode of connection - wired better than wireless
3. Signal quality - range, interference or physical obstructions
4. Network topology
99
What are the different network topologies?
1.Star
2.Bus
3.Ring
4.Mesh
100
What is a client server network?
1.A network which is managed by a central server, which the clients all connect to
2.Files and software are stored centrally on the server
3.Most of the internet runs on this topology
101
How does a client server network work?
1. Clients send a request to the server
2. The server processes the request and responds
3. This is the client server relationship
102
What are the pros of client server networks?
1.Easy to keep track of files
2.Easy to perform backups
3.Easier to install and update software
4.Easier to manage network security
5.Servers are reliable
103
What are the cons of client server networks?
1. Expensive to set up and needs IT specialists to maintain
2. Server dependence
3. The server could become overloaded if too many clients are accessing at once
104
What is a P2P (Peer to peer) network
1.All the devices are equal and connect directly to eachother without a central server
2.Often used in homes to connect devices and printer
105
How does a P2P network work?
The files are stored on individual devices and are shared with others
106
What are the pros of P2P
1.Easy to maintain - no experts required
2.No server dependence
107
What are the cons of P2P
1.No centralised management - important software must be installed individually
2.Backups are harder to make
3.Hard to keep track of files
4.Data may be lost if a client fails
5.Machines slow down when other devices access them
108
What is STAR topology?
1.All devices are connected to a central switch or server which controls the network
2.The central switch allows many devices to access the server simultaneously
3.Star networks may be wired or wireless
109
What are the pros of star topology?
1.If a device fails or a cable is disconnected, the rest of the network is ok
2.It's simple to add more devices
3.Better performance as data goes straight to the central device so all devices can transmit at once.
4.Few data collisions
110
What are the cons of a Star topology?
1. In a wired network, every device requires a cable which is expensive
2. If there is a problem with the server/switch, the whole network is affected.
111
What is bus topology?
1.All the devices are arranged in a line and connected to a backbone cable
2.Devices then send data in both directions along this cable to other devices
112
What is the problem with bus topology?
There is a lot of data travelling in different difections on a single wire, this causes data collisions, slowing the network
113
What is Ring topoology?
1. Data moves in one direction around a ring which connects all devices
2. This prevents collisions
114
What is the problem with ring topology?
1.Only one device can send data at a time, and data passes through many devices before reaching its destination.
2.If there is a problem with 1 cable/device it breaks
115
What is a mesh topology?
1.A mesh topology is a relatively new network layout
2.It is decentralised, where all devices are either indirectly or directly connected to eachother without a server or switch
116
How does a mesh topology work?
1.They send data along the fastest route to its destination using the connection available.
117
What are the pros of mesh topology
1. There is no single point where the network can fail as data can take multiple routes to its destination
2. Wireless technology make it a very practical option
118
What are the cons of mesh topology?
1.Used to be very expensive, as you need a lot of wires to connect the devices
119
What is the difference between full/partial mesh
1. full is where the devices are all connected together perfectly
2. Partial is where the device are not all connected to eachother.
120
What is a network standard?
A set of agreed requirements for hardware and software
121
Why are network standards important?
so that manufacturers can create products/programs which are compatible with other products/programs from other manufacturers.
122
What is a network protocol?
a set of rules for how devices communicate and how data is transmitted across a network.
123
What are communication protocols?
These specify how communication between 2 devices must start and end, how the data must be organised and what the devices must do if data goes missing.
124
What are MAC addresses?
MAC addresses are unique, unchangeable 48/64 bit codes which are assigned to all network enabled devices by the manufacturer.
125
How are MAC addresses made easier to use?
we convert them into hexadecimal.
126
Where are MAC addresses used?
1. When communication occurs on a single network
2. Mainly used by the ethernet protocol on LANs. The LAN switches read the MAC addresses and use them to direct data to the right device.
127
When are IP addresses used?
When sending data between TCP/IP networks (When sending data between different networks)
Eg - the internet
128
How are IP addresses assigned?
They are either assigned manually or automatically before the device can access the network.
129
What are the 2 versions of IP addresses?
IPv6 (128 bits) and IPv4 (32 bits)
130
Why was IPv6 created?
There were too many devices which needed a unique IP address.
131
How many IPv4 vs IPv6 addresses are there?
IPv4 = 2^32
IPv6 = 2^128
132
How are IPv4/6 addresses split?
1. IPv4 is split into 8 bit chunks, and each one is given as a denary number
2. IPv6 is split into 16 bit chunks, and each one is given as a hexadecimal number
133
What is TCP/IP
1.Transmission Control Protocol/Internet Protocol dictates how data is sent between networks, eg the internet
2.It is made up of 2 protocols.
134
What 2 protocols is TCP/IP made of?
1.TCP - Transmission Control Protocol
2.IP - Internet Protocol
135
What does TCP do?
1. Sets the rules for how devices connect on the network.
2. It splits data into packets and reassembles these packets into the original data once they reacch the destination
3. It checks wether the data is correctly sent/delivered
136
What does IP (protocol) do?
Internet Protocol is responsible for directing packets to their destination across a network.
137
What network protocols are there?
1.TCP
2.IP
3.HTTP
4.HTTPS
5.FTP
6.POP3
7.IMAP
8.SMTP
138
What does HTTP and HTTPS do?
1.HTTP - Hyper Text Transfer Protocol is used by web browsers to access websites and communicate with web servers
2.HTTPS - Hyper Text Transfer Protocol Secure - Same as HTTP but encrypts all information sent and received
139
What does FTP do?
File Transfer Protocol is used to access, edit and move files between devices on a network.
Eg - file from server to client
140
What does POP3 do?
Post Office Protocol version 3 is used to retrieve emails from a server. The server holds the email until you download it, at which point it is deleted.
141
What does IMAP do?
Internet Message Access Protocol is used to retreive emails from a server. The server holds the email until you actually delete it - you only download a copy. This is used by most web based email clients.
142
What does SMTP do?
Simple Mail Transfer Protocol is used to sent emails. It's also used to transfer emails between servers
143
What is a network layer?
A group of protocols which have similar functions and are self contained.
144
What are the advantages of using layers?
1. It breaks the network communication into manageable pieces. This helps developers concentrate on only one are of the network.
2. As layers are self contained, they can be changed without the other layers being affected
3. Having standards for each layer forces companies to make compatible, universal hardware and software, so different brands will work with each other and always work in basically the same way.
145
What is a URL?
Uniform Resource Locators are addresses used to access web servers and resources on them.
146
What is the WWW
The World Wide Web is a collection of websites that are hosted on web servers and accessed through the HTTP protocol.
147
What is DNS
Domain Name Service is used to translate websites domain names into IP addresses. It uses a Domain Name Server which stores the IP addresses which match to the correct domain names.
148
What are the pros of the Cloud?
1. Users can access files and apps from any connected device
2. Easy to increase how much storage is available
3. No need to buy expensive hardware to store data or run complex apps
4. No need to pay IT staff to manage the hardware
5. Cloud host provides security and backups
6. Cloud software will be updated automatically.
149
What are the cons of the Cloud?
1.Need a connection to the internet to access files or apps
2.Dependent on host for security and backups
3.Data stored in the cloud can be culnerable to hackers
4.Unclear who has ownership over cloud data
5.Subscription fees for using cloud storage and apps may be expensive.
150
What are the 3 types of malware?
1.Virus
2.Trojan
3.Worms
151
What is a virus?
1.Malware which attaches by copying itself into certain files.
2.Users spread them by copying infected files and activate them by opening the file.
152
What are worms?
1.Like viruses but they self replicate without any user help, meaning they can spread quickly.
2.They exploit weaknesses in network security.
153
What are trojans?
1.Malware disguised as legit software. Unlike viruses and worms, trojans don't replicate themselves. Users install them not realising they have a hidden purpose.
154
What is scareware?
Malware which tells the user their computer is infected with loads of viruses, and scares them into following instructions
155
What is ransomware
Malware which encrypts all the files on a computer, the data is held at ransom in exchange for a key.
156
What are rootkits?
Malware which alter permissions, giving malware and hackers admin level access
157
What is phishing?
When criminals send emails or texts to people claiming to be from a well known business. They then request the user to perform a task for their personal gain.
158
What is social engineering?
The way of gaining sensitive info or illegal access to networks by influencing people.
159
What are SQL injections?
Pieves of SQL typed into a website's input boc which then reveal sensitive information.
160
What can organisations do to protect their networks?
1.Regularly text the network to fin and fix weaknesses
2.Use passwords
3.Enforce user access levels
4.Instal anti malware and a firewall
5.Encrypt sensinsitive data.
161
What is penetration testing?
1.when organisations employ specialists to simulate potential attacks on their network
2.It is used to identify possible weaknesses in a network's security.
162
What physical security options are there?
1. using locks and passcodes to restrict access to important physical areas like server rooms.
2. Use CCTV
163
What are firewalls/
Firewalls block unauthorised access by examining all data entering and leaving the network.
164
What is encrypted text called?
cipher text
165
What health problems can be caused by tech?
1.repetitive strain injury (RSI)
2.Eyestrain
3.Back problems
166
what is RSI
Repetitive strain injury, where repetitive movements damage parts of the body, eg carpal tunnel
167
What are the 3 computer legislation laws?
1.Data Protection Act 2018
2.Copyright, Designs and Patents Act 1988
3.The Computer Misuse Act 1990
168
What are the 6 parts to the Data Protection Act 2018
1. data must only be used lawfully
2. data must only be used for the specified pupose
3. data should be adequate, relevant and not excessive
4. Data must be kept up to date
5. data should not be kept longer than necessary
6. Data should be kept safe and secure
169
What 4 things does the Computer Misuse Act 1990 prevent?
1. gaining unauthorised access to a private network or device
2. Gaining unauthorised a network or device in order to commit a crime
3. Unauthorised modification of computer material eg deleting or changing files
4. Making, supplying or obtaining malware.
170
What is open source software?
1. Software where the source code is made freely available.
2. Users can legally modify the source code to create their own version, which can be shared under the same terms as the original
171
What are the pros of Open source software?
1. Usually free
2. Made for the greater good, not profit
3. Software can be changed to suit your needs
4. Popular software can easily be fixed due to the large community
172
What are the cons of Open source software?
1.Small projects
2.could be buggy
3.security flaws
4.no warranties
5.no dedicated customer support
6.Some companies won't be able to keep their code secret
173
What is proprietary software?
Software where only the compiled code is released. The source code is a guarded secret.
174
What are the pros of proprietary software?
1. Comes with warranties and customer support
2. Should be well tested and reliable.
3. Updates are more regular
4. cheaper for companies, rather than developing their own
175
what are the cons of proprietary software?
1. Can be expensive
2. Software may not fit user's needs
3. May not get updates after a while
