A network is a group of computers connected to a centralized hub so they can share information and resources. You might use a network to send files from one computer to another, or you might set up a network for communication among employees in a business environment. A network can also be used to connect with other networks over the Internet, a connection that allows you to share data and resources across long distances. A network is made up of many devices, including switches, routers, wireless routers, and access points.
The most common way to connect devices to a network is to use twisted pair Ethernet cabling. These cables run over coaxial cable, telephone wires, or power lines. Depending on the type of network topology, different types of networking media can be used. For example, optical fiber cabling uses light to transmit data, so it is not affected by electromagnetic interference (EMI).
There are many other ways to connect devices to a network. For example, power line networking is a popular technology that turns the existing electrical wiring in a building into network cables. Using adapters that are plugged into wall sockets, these wires can carry data signals and support a variety of network protocols, including Ethernet. Some powerline adapters also provide Wi-Fi connectivity. Other networking technologies use radio waves, lasers, or infrared beams to enable network connections. Almost every modern personal computer, smartphone and tablet has a built-in Ethernet port or a Wi-Fi chip to allow you to connect with a network over these technologies.