What Is a LAN? Local Area Networks Defined

A local area network (LAN) is a group of computers or other devices connected together in a specific location, sharing a single Internet connection. Devices connect to this type of network either by WiFi or Ethernet cable through routers, access points, and servers. These networks can be as small as two or three connected computers or devices in a private home, or they can be as large as thousands of devices in a corporate office.

Purpose of a LAN

A local area network was first used at colleges and universities in the 1960s to share class schedules, grades, library resources, and other information. With the development of the Ethernet cable in the 70s, many businesses began to use LANs to share files and access printers.

Today, we use LANs in homes and offices for sharing resources, printers, files, and other data. You can also play multiplayer videogames on a local network. If you have a network in your own home, chances are good you use a local area network.

How do LANs work?

In general, local area networks consist of various cables and switches. They connect to routers and modems to deliver Internet access. The switches assist in facilitating communication between devices connected on the network; they increase the number of ports open to receive connection on the network.

With peer-to-peer local area networks, the switches and routers are able to share data directly, without even the use of a central server. Some local area networks also consist of firewalls, load balancers, and network intrusion detection devices.

A LAN is different from other computer networks because all of the devices need to be in the same physical location, such as in a home, school, or office building. The devices connect to a router or server via cable, such as with a twisted pair Ethernet, or via WiFi connection.

Each device in a local area network has its own private IP address, which users can change for more privacy. However, the local area network has one public IP address that these devices operate under. This is the IP address shown to the rest of the Internet when you go online.

A router heading a local area network (LAN)

Two types of LAN

There are two types of local area network connections: client/server LANs and peer-to-peer LANs. Both work the same generally, but they are structured differently. Which network you want to use depends on several factors, such as the amount of connections you need and the tasks you want to perform on the network. Here, we'll distinguish between the two so that you can determine which local area network would work better for you.

Client/server LANs

Client/server LANs are made up of multiple devices, or clients, connected to one server. The server controls the network traffic in addition to file storage and sharing and printer access. Clients in this type of network can be desktop personal computers, tablets, phones, and any other network-enabled devices. Devices can connect to the server via Ethernet cable (LAN cable) or Wi-Fi connection (wireless LAN).

You can use many applications, including file sharing apps, email, printing, and databases. An IT or network administrator manages access to these applications.

Schools and large businesses usually use client/server networks.

Peer-to-peer LANs

Peer-to-peer LANs differ from client/server in that they do not have a centralized server that manages the traffic. Instead, all the devices on the network equally handle the traffic themselves. For this reason, peer-to-peer networks can't handle heavy network traffic.

Peer-to-peer networks are typically limited to homes and small businesses such as restaurants or coffee shops. They work better in these environments, as they lack the capacity for broad connections that client/server LANs have.

Networks beyond LANs

A local area network has the ability to connect to other local area networks in one of two ways: via leased lines or via the Internet. Multiple interconnected LAN systems becomes a wide area network, or WAN. These, as well as metropolitan area networks (MANs), have a larger range than LANs, but they work similarly.

Metropolitan area networks (MANs) are used when an organization has multiple buildings within a city or local space. With these types of networks, buildings connect to each other using fiber optic cables provided by the local telecom company.

Wide area networks (WANs) are larger than metro networks and can cover regions, countries, or even the whole world. As mentioned above, they are made up of smaller local area networks joined together to reach a broader area.

Benefits of a LAN

The key benefit of using LAN is that multiple devices can access the Internet with just one connection. It allows for easy communication, file sharing, and printing. Furthermore, you can control connected devices, like security cameras or other smart devices, with your smartphone or computer.

Setting up a home network is a good way to connect all of the smart devices in your home, from your video game systems to your security system to your refrigerator. Connected devices can easily share and access data among devices.

Just like any other network, you should secure your LAN. For client/server connections, you can change security settings in the L2/L3 switches. For home networks, you can change security settings by accessing the admin page for your router. Additional security tools include fingerprint recognition, encryption, and antivirus software.

Furthermore, many users choose to install firewalls behind access points on their network. WiFi Protected Access and its successor, WPA2, help with password encryption on any incoming Internet traffic to help defend against viruses or hacks. Virtual privacy networks, or VPNs, also help secure the access points on your local area networks.