A LAN is a network that connects computers, printers, cameras, servers and other devices at a single location — an office, a shop or a warehouse. It can be wired, wireless (Wi-Fi) or both.
Inside a LAN, devices exchange data quickly: a computer prints to a network printer or saves files to a shared folder. To reach the internet, the LAN connects to the outside world through a router.
Example
An office with 20 computers, 2 printers and a file server all connected to one switch — that is the office LAN.