A computer network allows two or more computers to share data and communications. Most election management bodies (EMBs) will want to connect their computers in networks to allow data sharing within the EMB and with outside organisations and the internet.
Types of networks include:
- local-area networks (LANs)
- wide-area networks (WANs)
- the internet
- intranets
- extranets
Local-area networks (LANs)
LANs connect computers and other devices such as printers within an office or similar limited physical area. LANs are connected by permanent cables that allow rapid data transfer. A LAN will generally comprise several personal computers, shared peripheral devices such as printers and scanners, and a central file server with high-capacity disk storage. A network server stores data and programs that can be used and shared by any computer linked to the LAN (subject to users having access rights - see Data Access Security).
A LAN requires special operating system software to allow the various devices connected to the LAN to communicate with each other.
In addition to the benefits derived from users sharing common data and programs, use of LANs allows systems administrators to impose standards on users and to ensure data is systematically backed up. With a LAN, users can be required to store data on the central file server rather than their local hard drives, thereby ensuring that data administration can be centrally managed and backed up, and ensuring that data is available to all authorised staff on the LAN.
Wide-area networks (WANs)
Several LANs can be connected together to create a wide-area network (WAN). WANs can allow geographically dispersed computers to communicate with each and to share data. For example, an EMB with several different offices, each with its own LAN, can have an EMB-wide WAN, allowing data to be shared across the organisation.
WANs can be used to link computers from anywhere in the world with access to appropriate telecommunications. WANs can be linked by cables or optical fibres, or by microwave links or radio links, using ground-based or satellite transmitters. These links can be privately owned, but they are more commonly part of the public telecommunications infrastructure (see Telecommunications).
WANs tend to be organisation-specific, allowing an organisation to connect all its employees into one network regardless of their physical locations. Many users will not see the distinction between their LAN and their WAN.
The internet
The largest WAN is the internet , a collection of networks linking millions of computer users around the world. For more information about electoral uses of the internet, see The internet.
Intranets
An intranet is a WAN that is set up like the internet, but access is limited to authorised users only. For example, an EMB may set up an intranet containing an in-house website that is accessible only by the EMB, for administration and training purposes.
Intranets also tend to be organisation-specific.
Extranets
An extranet is similar to an intranet, but it generally allows users from several different organisations to obtain access. An extranet is used where data, particularly web-based, is shared between organisations but the users do not want to allow unauthorised access to the general public, as is available on the internet.
