A network is a group of computers, printers and other devices that are connected together with cables. Each computer, printer, or other peripheral device that is connected to the network is called a node.
Networks can have tens, thousands, or even millions of nodes.
This is because most of the data and user account information is stored on a centralized server computer instead of being distributed across all the computers in the network. I n order for a network to function properly, the network engineer must follow certain rules. For example, cables have limits as to their total length and placement. The layout or design of a network is called its topology. Because it's relatively inexpensive, easy to set up and maintain, and can transmit data at very high speeds, Ethernet is the most popular topology in use today.