Introduction
What is the difference between a LAN, WAN, and a Subnet? Now the first thing we must do is define what a network is. Now simply put, a network at its most basic are just computers connected to each other to exchange information. These computers can be connected by using either a cable or a wireless connection.
Table of Contents
LAN (Local Area Network)
Now the most common way for computers to connect to each other is by using a switch. A switch is a central wiring point with multiple ports so that two or more computers can connect to each other to create a network. So since we have created a network, this is called a LAN or local area network. And a LAN is a private network. It’s a type of network that you would find inside of a building such as in a home, business, or an organization. So right now the computers in this network can only talk and exchange data with each other.
WAN (Wide Area Network)
However, if these computers need to access another network such as the internet, they would need to contact an internet service provider and then that ISP would send them a device called a gateway. Now a gateway is a modem, router combo. Then once the gateway is connected, the computers in this local area network can now access and be a part of a wide area network or WAN. A wide area network is a large network of millions of computers that spans over a large geographical area, such as a country, continent or even the entire globe or in other words the internet. The internet is an example of a wide area network.
Subnet (Subnetwork)
Now a lot of times what may happen in a lot of businesses is that they may have different departments. For example, they may have a service department and a sales department. And a lot of times that business may want to separate the computer network data in the different departments from each other so that the sales department doesn’t see any network traffic from the service department and vice versa.
So what a business will do is that they’ll divide their one local area network into two smaller networks. These smaller networks are called subnetworks. And a shorter way to say subnetwork is subnet. A subnetwork or subnet is just a division of a bigger network. So this network here is still a local area network but within that LAN we have two subnetworks or subnets.
How Subnets Work
Now what divides or separates a network from another network is a router. A router is the doorway or gateway to a network. So this router here is what’s separating these two subnets. Now this network is not just limited to creating just two subnets, it can create how many it wants it just depends on the needs of the business.
So if this business expanded and they wanted to create another department, they can further separate this network and create a third subnet by adding another router. So now this local area network has three subnetworks or subnets. So as I stated before the reason why an organization or business would create subnets is to separate the network traffic.
Reasons for Subnetting
Now this could be for several different reasons, such as manageability. Because if any problems happen on a network it would be easier to pinpoint on smaller networks than one large network. And another reason is for security. Subnets can have their own separate security rules to either allow or deny access to certain data. And another reason for creating subnets is to improve the performance of a network by controlling broadcast traffic.
When a computer wants to communicate with other computers on a network it sends out a broadcast to every computer on the network. So every computer can hear the broadcast traffic from every other computer. But by breaking down a network into smaller subnets, which is known as subnetting, the broadcasts are only heard by other computers on the same subnet, therefore limiting the amount of broadcast traffic.
Conclusion
So as a review, the internet with all of its computers, servers, and routers is an example of a wide area network. But within that wide area network we have local area networks. These are private networks that are in organizations, businesses, and homes. And within those LANs we have subnets which are divisions of larger networks.