A network is a set of devices (nodes) connected by media so they can share resources files, printers, applications and Internet access using an agreed set of rules called protocols.

• End devices: where a message originates or ends (PCs, phones, servers, printers).
• Intermediary devices: switches, routers, wireless access points that move data along the path.
• Network media: copper cable, fiber or wireless that carries the signal.
• Protocols: the rules that govern format, timing and delivery of messages.