What is a LAN and how does it work?

Today almost every home owns smart devices such as computers, smartphones and smart TVs that can connect to the internet. These devices can reach each other, and the internet, through a LAN. So what is a LAN? What does it do and what are its features? Find out with Mona Media in the article below.

What is a LAN?

LAN is short for Local Area Network. It means a local computer network. It lets devices connect to one another so they can work together and share data. The connection is made through LAN cable or Wi-Fi (wireless) in a small space, so it only works within a limited area such as an office, a home or a school.

The two basic types of LAN

There are two main types of LAN: wired LAN and wireless LAN.

• Wired LAN uses switches and Ethernet cables to connect end devices, servers or Internet of Things (IoT) devices to the company network. A small business with only a few devices can use an unmanaged LAN switch with enough Ethernet ports to connect everything.

Larger LANs that connect thousands of devices, however, need extra configuration steps and hardware to keep the network running well. This is where the virtual LAN (VLAN) comes in. A VLAN splits traffic on one physical network into two or more separate networks, which makes the network easier to manage, especially a very large LAN.

• Wireless LAN (WLAN) uses the IEEE 802.11 specification to carry data between end devices and the network over a wireless spectrum. In many cases a wireless LAN is preferred over a wired one because it is flexible and saves money, with no need to run cable through the whole building. Companies treat WLAN as a primary way to connect, because many users depend on smartphones, tablets and other mobile devices.

What are the components of a LAN?

A local computer network is made up of several components:

• Server: this is the main device on the network. It manages connections and information sharing among the parts of the system, and more. In some cases, though, all devices have equal rights and there is no server.
• Clients (workstations): devices that are connected to one another and managed by the server.
• Network interface card (NIC): the part that sends and receives network signals to the devices in the LAN so they can communicate and exchange data. A network card contains a signal transmission controller and a transceiver that converts data into signals and back. It sits in a slot on the computer's motherboard and is built into most laptops today.
• Network cable: the medium that carries signals between the devices in the system. A LAN usually uses two kinds of cable: coaxial and twisted pair.
• Repeater: a device that amplifies the signal so it travels farther than the original. In a local network the transmission limit is usually about 100 m, but a repeater can extend well beyond that.
• Hub: is similar to a repeater but has more ports, amplifying the signal from one port to several others.
• Bridge: a device that joins two different networks into one.
• Switch: a device like a bridge but with more ports, used to link several segments together.
• Router: a device that forwards data packets across an internetwork to their end points through routing. A router can also link different LANs even over long distances.
• Gateway: a device that connects networks using different protocols.

How a LAN works

The function of a LAN is to link computers together and give them access to, or sharing of, printers, files and other services. LAN architecture is classified as peer-to-peer (peer-to-peer) or client-server. In a client-server LAN, client devices connect to a central server. There, access to applications, devices and file storage, as well as network traffic, is managed.

Applications running on a LAN server provide services such as access to database, document sharing, email and printing. Devices on a peer-to-peer LAN share data directly through a switch or router, without needing a central server.

A LAN can be connected to other LANs through leased lines or services, or over the internet using virtual private network technology.

What a LAN is used for

A LAN offers these networking benefits:

• Lets devices such as laptops, phones and computers connect to one another
• Gives access to centralized applications hosted on servers
• Lets every device store important business data in one central place
• Protects the devices connected to the LAN with network security tools.
• Lets users share resources, including printers, applications and other shared services
• Lets many devices on a LAN share a single internet connection

Basic LAN topologies

A LAN topology is the way the elements of a network are arranged and how they connect to one another. There are many types, but most are built from 3 common ones:

Star topology

A star network has one central point, and the workstations and other devices are the remaining nodes. The center controls all network activity, such as:

• Announcing the status of the network.
• Identifying the sender and receiver address pair and letting them take the line to communicate with each other.
• Monitoring and handling errors in the exchange of information, and so on.

Bus topology

A bus network is laid out like a corridor, with devices attached along a main line that carries the data. Both ends of the main line are closed off by two terminators. Data moving up or down the network must carry the destination address.

Ring topology

The last common type is the ring network. It is laid out and installed as a closed circle. Signals travel in one direction, and at any moment each workstation passes the signal on through only one node. Information sent must carry the specific address of the station that will receive it.

That is the general information answering the question "what is a LAN?". We hope the article has helped you understand how important a LAN is. May it give you a good overview of the LAN and help you get the most from its benefits.

You may also be interested in:

• What is the internet? An overview
• What is a VPN (virtual private network)? How does a VPN relate to security technology?