Section 4 Flashcards
What is a computer network?
Two or more computing devices connected together in order to share resources.
Give 3 advantages of computing networks
Share hardware eg. printers
Share software and software is likely to be cheaper (licences)
Easier to communicate
Data can be backed up on a server
Easy to share files
Security is good - users cannot see others’ files unlike on stand-alone machines.
Give 3 disadvantages of computer networks.
Purchasing the network cabling and file servers can be expensive.
Viruses can spread to other computers throughout a computer network
Managing a large network is complicated, requires training and a network manager usually needs to be employed.
If the file server breaks down, the files on the file server become inaccessible.
Danger of hacking.
What does LAN stand for?
Local Area Network
What does WAN stand for?
Wide Area Network
What is a LAN (Local Area Network)?
A network that covers a small geographical area.
What is a WAN (Wide Area Network)?
A network that covers a large geographical area.
Give 2 examples of a LAN (Local Area Network).
Examples of a LAN include; School network, router, local CCTV system. The hardware is typically privately owned.
Give 2 examples of a WAN (Wide Area Network).
Examples of a WAN include; the internet, ATM, mobile-phone network, GOS (Satnav). The biggest WAN in the world is the internet.
What are protocols?
Protocols deal with the rules that define how data is transmitted over a network. They ensure a standard, consistent functionality that allows the client and the server to understand each other.
What does HTTP stand for?
Hypertext Transfer Protocol
What is a HTTP (Hypertext Transfer Protocol)?
Used to view a website using a web browser.
What does SMTP stand for?
Simple Mail Transfer Protocol
What is a SMTP (Simple Mail Transfer Protocol)?
Used to send an e-mail from one mail server to another.
What does IMAP stand for?
Internet Message Access Protocol
What does FTP stand for?
File Transfer Protocol
What is a IMAP (Internet Message Access Protocol)?
Used to download an e-mail to your computer.
What is a FTP (File Transfer Protocol)?
Used to transmit a file from a client to a server.
What is a Network topology?
The structure of the way that separate devices (nodes) are connected.
A network can be connected with wires, optical fibre or wirelessly, so that separate devices (also known as nodes) can communicate with one another and transfer data. The structure of the way the nodes are connect is called network topology.
Name the 4 types of network topology.
Bus, Ring, Star, Mesh
Give a pro and a con of a bus topology.
Pros: Cheap and easy to install
Cons: Performance suffers as you add PCs.
Give a pro and a con of a Ring topology.
Pros: Fast
Cons: If one line breaks, the whole network is affected.
Give a pro and a con of a star topology.
Pros: Fast
Cons: Needs a lot of cabling
Give a pro and a con if a mesh topology.
Pros: Has most redundancy
Cons: Expensive
What is the Internet?
A global computer network that connects networks and individual computers, and uses standardised communication protocols and data packets to provide a variety of information and communication facilities. It is a public network with open access. A web browser (e.g. Chrome) allows you to find and view websites on the internet.
What is the intranet?
Intranets operate in a similar way to the internet and although they are still networks, they are usually private and are used to send information securely and safely. Unlike the internet which is a global network accessible by all, access to an organisation’s intranet is restricted and only accessible to authorised users such as employees.
What is the Extranet?
An extranet is a private intranet that also allows access by selected parties that reside outside of the organisation. These parties, for example, may be customers, key stakeholders or clients. External users will have an authorisation level once they have successfully logged in which will determine which resources they may access. An example at a school could be parents being allowed access to a certain area to see their child’s reports.
Give 3 similarities between Internet/ intranet/ extranet.
They all use web-based technologies
They allow users to access information remotely
They all use client server architecture
They all use security measures such as authentication and encryption
They all promote and facilitate information and resource sharing