Networks and Topologies

A local area network covers a small geographical area. It consists of computers and peripheral devices (e.g. printers) connected together usually on a single site.

A wide area network. A wide area network is a collection of computers connected to each other using the resources supplied by a third party carrier such as BT. It uses cables, telephone lines, satellites and radio waves to connect the component, which are usually spread over a wide geographical area

Bandwidth - The measure of the amount of data that can be transferred from place to another in a certain amount of time.Copper ethernet cables speed this up. Wireless slows it down. Interference - Packets need to be retransmitted which increases the time taken. Latency - The measure of delay. Measures the time it takes for data to get from one place to another

In a client server network the server is a powerful computer which provides services or resources required by any of the clients. The client is a computer which requests the services or resources providedd by the server.

In a smaller office it is not cost effective to have someone run the network. So the computers will be cabled or wirelessly connected together. This is called peer-to-peer as all the computers have equal status as each other.

All of the computers have their own cable connecting them to a hub,switch or computer which acts as a server. adv - if one cable fails the other workstations aren’t effected disadvantage - can be costly to install because there is a lot of cabling and extra hardware.

A hub is a hardware device which enables multiple devices or connections to connect to a computer.

A wireless access point receives data from a netwwork via its physical connection. The transmitter converts data to radio waves which are transmitted. Any device on the network receives this signal via a Wi-Fi adaptor.

A switch is a component of a LAN that finds the MAC address of each device connected locally. Its function is to forward inbound packages to only its recipient’s MAC address.

A router is designed to route data packets across wide area networks like the internet. Each router in a network acts a node so data packets are passed between node to node till the correct destination.

a network interface card is required to connect any network enabled device. This can be a physical component or operates wirelessly. All devices connected to the internet have a NIC

A mesh topology has every single device connected to the internet. A full mesh network had each and every node connected to every other node. A partial mesh network, some nodes are not directly connected. Only one node needs to be physically connected to a modern. This is used in a LAN

When you enter a URL into the internet it goes to the DNS system which maps the domain names to IP addresses so it can translate to a domain name. If an IP address is not found then it is sent to the next DNS server

Hosting is where you pay for an internet company that stores your files and makes them available to you or others from internet connected computers. Web hosting includes domain name registeration which makes sure the name chosen has not already been taken and is acceptable.

The cloud is a software which saves data offsite using a third party storage system, for example dropbox, google, microsoft.

You can access it from anywhere You can share data with other people in different locations backup is no longer an issue as it is the responsibility of the provider You can access using the internet

You are dependant on having an internet connection in order to acces your data Some users are concerned about the security of data in the cloud

A webserver is a specialised computer with the role of hosting your organisation websites. There is also a server which gives all the resources required by the client