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Networking

LAN: Local Area Network, Computers and peripherals in close proximity typically one building or site that has been connected together.

 

WAN: Wide Area Network, A set of links that connects geographically remote computers and local area networks.

 

MAN: Metropolitan Area Network, a city wide network linked by cables or microwaves. e.g. a city Wi-Fi.

 

Internet the international network of interconnected computers, sometimes called a network of networks. It is the physical infrastructure i.e. cables and servers.

 

World Wide Web the collection of web pages and multimedia resources available on the internet.

 

Intranet is a service that uses internet technologies (protocols) to distribute information securely and privately within a single organisation over its internal network.

 

Extranet is an extension of a company’s private intranet where individuals can have authorised access to it by logging on securely over the internet.

 

Hub: small, simple and cheap device to connect network devices communication by broadcasting data and therefore less secure. Not used much nowadays.

 

Switch: More complex and expensive than hub and can direct packets. Connects at the data link layer.

 

Router: Most expensive and complex of the three, as it is programmable. It can set filters like keyword, blacklist and whitelist. Connects networks at the network protocol layer.

 

Protocol a description of a set of procedures / or known rules to be followed when communicating.

 

IP – Internet Protocol, a unique address that identifies a computer on a network. Allows packets to be directed from source to destination.

 

TCP – Transmission Control Protocol ensures that data is sent and received accurately (assemble or resend).

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