What is a LAN?
We already know two things about LAN from its name "Local Area Network"; namely that it is devices connected via a network and that the network and devices are local. This is what distinguishes LANs from other types of networks such as Wide Area Networks (WAN) and Metropolitan Area Networks (MAN).
LANs are typically used within a small area - usually just a single building, although this is not a strict requirement. The area can be your home or a small business, and it can be just a few devices. It can also be a much larger area such as an entire office building containing hundreds or thousands of devices.
Whatever the size, the defining characteristic of a LAN is that it connects devices in a single limited area.
The benefits of using a LAN are the same benefits of having any devices connected. Devices can share a single internet connection, share files with each other, print to a common printer and so on.
On larger LANs, you'll also be able to find dedicated servers that host services like global user directories, email and access to other shared company resources.
What kind of technology goes into a LAN?
The type of technologies used in a LAN is dependent on the number of devices and what services are provided on the network. The two basic connection types used on modern LANs regardless of size are Ethernet cables and Wi-Fi.
On a typical home or small office LAN, you might find a modem that provides an internet connection (and a basic firewall), a router that lets other devices share the connection and connect with each other, and a Wi-Fi access point so that they have wireless access. Sometimes these functions are combined into a single device. For example, many ISPs provide a combo device that serves as a modem, router and wireless access point. Sometimes you can also find devices called "switches" that let you split a single Ethernet connection into several different connection points.
On larger LANs, you'll typically find the same kind of networking tools on a larger scale - both in terms of the number of devices and how powerful they are.
