- Introduction to Networks -

What is a Network?

A network is defined as devices connected together to share information and services. The types of data/services that can be shared on a network is endless - documents, music, email, websites, databases, printers, faxes, telephony, videoconferencing, etc.

Protocols are “rules” that govern the method by which devices share data and services. Protocols are covered in great detail in subsequent sections.

Basic Network Types

Networks are generally broken down into two types:

LANs (Local Area Networks) - a high-speed network that covers a relatively small geographic area, usually contained within a single building or campus. A LAN is usually under the administrative control of a single entity/organization.

WANs (Wide Area Networks) – The book definition of a WAN is a network that spans large geographical locations, usually to interconnect multiple LANs.

A more practical definition describes a WAN as a network that traverses a public network or commercial carrier, using one of several WAN technologies. Thus, a WAN can be under the administrative control of several entities or organizations, and does not need to “span large geographical distances.”

MAN (Metropolitan Area Network). A MAN is defined as a network that spans several LAN’s across a city-wide geographic area. The term “MAN” is less prevalent than either LAN or WAN.