A network infrastructure is an interconnected group of computer systems linked by the various parts of a telecommunications architecture. Specifically, this infrastructure refers to the organization of its various parts and their configuration — from individual networked computers to routers, cables, wireless access points, switches, backbones, network protocols, and network access methodologies. Infrastructures can be either open or closed, such as the open architecture of the Internet or the closed architecture of a private intranet. They can operate over wired or wireless network connections, or a combination of both.
The simplest form of network infrastructure typically consists of one or more computers, a network or Internet connection, and a hub to both link the computers to the network connection and tie the various systems to each other. The hub merely links the computers, but does not limit data flow to or from any one system. To control or limit access between systems and regulate information flow, a switch replaces the hub to create network protocols that define how the systems communicate with each other. To allow the network created by these systems to communicate to others, via the network connection, requires a router, which bridges the networks and basically provides a common language for data exchange, according to the rules of each network.