Computer Science Revision

Question 1

Benefits Of Gaming:

Answer 1

Can Have the following effects:

• Improve your tracking if objects
• It can slow your brain from ageing by up to 7 years
• Help you become more sociable
• Can quicken your reaction time
• Can stimulate positive endorphins in your brain, making you feel happy
• Can improve your eyesight in reading small letters
• Can help relieve your brain from stress
• Can help your brain in computing certain colours at faster pace

Question 2

Drawbacks Of Gaming

Answer 2

Can Have the following effects:

• Can become addictive
• Can degrade your eyesight
• Can give you headaches
• Can kill brain cells
• The screen can deprive you of sleep
• It can dry out your eyes
• You could get RSI

Question 3

Trojan Horse

Answer 3

A Trojan Horse is a harmful piece of Malware, which can delete data, block data, change data and even copy it. It can also give hackers access to your system. The Malware gets into your system, via a legitimate looking piece of software either being opened up of downloaded onto the device.

Question 4

Virus

Answer 4

A Virus is a malicious peice of software, which has been loaded onto your device and can perform malicious actions. Viruses can spread through program in your computer by infecting one, and moving onto another. They can destroy, modify and put new information on your computer, as well as collecting valuable information, and making the computer laggy.

Question 5

Worms

Answer 5

A worm is unlike a virus in the fact that it requires no outside help to get into or spread across a system or network, as worms, unlike viruses are stand alone malicious programs. The can destroy files and documents and they can self replicate by themselves. Worms are often present in Peer-to-Peer Networks. Worms can get onto your system through email attachment, infected websites and infected downloads.

Question 6

Spyware

Answer 6

Spyware is generally defined as a software that is designed to gather data from another device and send it to a third party, weather that may be a hacker or a company, without the user’s consent. This can include Passwords, Credit Cards, Pins and more such as the things that you’ve typed in on your keyboard. It can also slow down your loading times. Spyware can be installed on an application, a computer or even a phone, which is done by attaching itself to a to another program in which the user regularly uses or downloads.

Question 7

Ransomware

Answer 7

Ransomware is another malicious software which it infects your computer and sends you messages demanding large sums of money to paid in order for the computer to work again. It also has the ability to lock a computer screen or encrypt files with a password. Once the money is paid, there is always no guarantee that the ransomware will come back again. Ransomware can get into your system by dodgy and questionable websites, suspicious email messages and downloaded attachments, or is your don’t install a firewall e.c.t.

Question 8

What is .co.uk

Answer 8

.co.uk usually means the webisite is used by a company or business, located in the UK. The .co, being company and the.uk, being the UK.

Question 9

What is .com

Answer 9

.com usually means that the website is either a commercial, or used for other commercial uses.

Question 10

What is .org

Answer 10

.org is usually used for an organisation, which is usually non-profitable, for example, charities.

Question 11

What is .sch

Answer 11

.sch is usually used by a school or teaching organisation/body.

Question 12

What is .gov

Answer 12

.gov is usually used by a government organisation and are only used for government organisations mainly in America.

Question 13

What is a Wide Area Network (WAN)?

Answer 13

A Wide Area Network is a network which usually stretches over 1km in radius from it’s computers. This is usually used by cables, telephone lines, satellites and radio waves.

Examples:
Internet and International Banking ATM machines.

Question 14

What is a Local Area Networks (LAN)

Answer 14

A Local Area Network is a network,a bit like a WAN network, but the LAN network has a much smaller radius, with it only supplying device which are a short distance away. They usually operate on a single site or within an institution and use cables and radio waves to connect to devices.

Examples:
The School Network and a Small Business Network

Question 15

What are the 3 types of Network Topologies?

Answer 15

Bus
Ring
Star

Question 16

What is a Bus Network?

Answer 16

A bus network is arrangement in a LAN, with each node (device/workstation) connected to one main cable. This comes from a Terminator, to the main cable and the branches off separately to each device and back again.

Question 17

Bus Network Advantages and Disadvantages

Answer 17

Advantages:

• The simplest and cheapest to install and extend.
• If one node (branch/device) fails, the rest of the network is not affected.

Disadvantages:

• If the Main Cable fails or break, then so does the rest of the network too
• The network will slow down greatly if there is too much traffic piled onto it.

Question 18

What is a Ring Network?

Answer 18

A Ring Network consists of a single Terminal and a Main Cable which is sent round in a circle, which each device connected to another, which creates a one way system for any tokens or packets sent to any devices.

Question 19

Ring Network Advantages and Disadvantages

Answer 19

Advantages:

-It is like a one-way system, so it is not affected by lots of traffic

Disadvantages:

• If the Main Cable fails, then it will affect the whole network
• To add more nodes, you will need to ‘break’ the ring too add them, disrupting the whole network
• All of the nodes have to be switched on for it to work.

Question 20

What is a Star Network?

Answer 20

A Star Network consists of one main Server, which is connected to a Switch or a Hub, which then connected to all the other devices separately, a little bit like the bus, but with the Main Cable going from the Server to the Switch/Hub.

Question 21

Star Network Advantages and Disadvantages

Answer 21

Advantages:

• Gives the fastest performance
• It is easy to install and expand to include more nodes
• If a Minor Cable breaks, then only the node is affected, not the rest of the network.

Disadvantages:

• Uses the largest amount of cables, making it quite expensive
• An extra Hub or Switch will increase the cost further

Question 22

What is a Router?

Answer 22

A router is a device that is usually connected to at least 2 networks and are known as ‘gateways’ which is where the 2 networks connect. A router separates and forwards the correct data packets along the networks.

Question 23

What is a Hub?

Answer 23

The more basic device which connect multiple devices or other network devices together. A Hub does not know how to send, or broadcast any type of data or information to any device.

Question 24

What is a Switch?

Answer 24

A switch is a device that connect other devices together and multiple data cables are plugged into it to allow the switch to send forward any data or information requested or needed by a device. This means the switch can communicate with other network devices.

Question 25

What is a Client-Server Network?

Answer 25

A Client-Server Network is one main powerful server acts as one great hub, which can serve less powerful devices, which are it's clients. An example would be a Google Server room, in which clients connect to, to use their Google Drive, or Google Docs and Slides (and many more).

Question 26

Client-Server Network Advantages and Disadvantages

Answer 26

Advatages: - All data can be backed up centrally, rather than on each individual computer - Anti-Virus software can be kept up to date and run by the server - Security is better because data is held in one location, rather than all over the organisation. - Users can log in from any computer or device in the network Disadvantages: - It is very, very expensive to install - If the server goes down, the whole of the rest of the network goes down with it. - The server can get overloaded, if too many people are using it

Question 27

What is a Peer-to-Peer Network (P2P)?

Answer 27

Peer-to-Peer networks are computer systems which are connected to each other through the internet. If these are intercepted and broken into, the can be easily hacked into. The network is does not need a central server. The Peer-to-Peer network becomes a file server as well as a client.

Question 28

Peer-to-Peer Advantages and Disadvantages

Answer 28

Advantages: - A printer or scanner, for example, can be shared - Each user has access to another computer in the network - A single router can provide access to the internet for all users on the network. - It is easier and less expensive to set up than a Client-Server Network Disadvantages: - Each user can access data on another computer in the network - Files and folders cannot be centrally backed up, like in a Client-Server Network.

Question 29

Advantages of Cloud Computing

Answer 29

Cloud Computing is when you can centrally back up all of your information and files onto a server hosted by the internet, where the information can be stored on an information warehouse, which is the server provider's cloud.

Question 30

Disadvantages of Cloud Computing

Answer 30

Advantages: - You can access your data and applications from anywhere, at anytime - You don't need a powerful computer with a big hard drive, everything is stored and run on a a remote computer - Backing up data is no longer 100% necessary, as it is done by the service provider Disadvantages: - The idea of handing over important data and information to another company worries some people. - Sensitive data could be hacked and/or stolen - You usually have to pay for extra storage space if you fill up your free allowance