Computer networks and topologies - Cambridge OCRNetworks

A network is two or more computers (or other electronic devices) that are connected together for the purpose of communication. They are connected by a wired medium such as cables, or by a wireless medium such as Wi-Fi.

A computer or device that is not connected to a network is called a stand-alone.

Today, many different types of computer are connected to some form of network. As well as PCs, many other devices can be connected, such as smartphones, smartwatches, fitness trackers, car engine management systems, internet-enabled fridges, intelligent personal assistants and media boxes.

Advantages of using networks

Computer networks bring a number of benefits:

• file sharing - users can share files with other users
• hardware sharing - users can share hardware, such as a printer
• communication - users can communicate via email, chat, or by video
• roaming access - users can sign in to any computer on the network and be able to access their files

On larger networks, such as those used by businesses and schools, there are additional benefits:

• centralised maintenance and updates - network managers can apply software updates across a network, removing the need for a user to worry about having to do so
• centralised security - anti-virus software and firewalls can be implemented across a network, helping to protect user files from risks
• user monitoring - network managers can monitor what users do on a network
• levels of access - different users can be given different access rights. This gives network managers the ability to generally restrict user access to certain files, while granting permission to specific users

Disadvantages of networks

Computer networks can also bring several problems:

• cost - additional equipment is needed to allow computers to communicate
• management - networks require management by technical staff such as a network manager
• spread of malware - viruses and other forms of malware can easily spread across an improperly secured network
• hacking - once a device is connected to another device, it is possible that data may be accessed without the device owner's permission