The Meanings of “Area Network” Acronyms – The difference between LAN, WAN, SAN, GAN, CAN

Another common question that I’ll get is something along the lines of:

  • What’s the difference between a LAN and a WAN?
  • What’s the difference between a CAN and a GAN?
  • What’s the difference between a LAN and a SAN?
  • What’s the difference between a WAN and a GAN?
  • Etc…

I was a bit hesitant about answering these kinds of questions at first.

For this blog, I wanted to be very careful about approaching the topic of networking. This is a complicated field that actually requires quite a bit of formal study to grasp. My goal in providing networking information is simply to help you communicate more easily with technical staff and outside consultants when making IT decisions.

When it comes to defining specific types of networks, you’re likely to hear different infrastructure topologies described as one of the following:

Local Area Network: This is the simplest and most common type of network. Most LANS exist within a very small geographic area, or even within the same building. The wireless network in your home can be said to be a type of LAN.

I’ve included a drawing below to provide context. Please forgive my horrible MS Paint Skills.

LAN topology

Campus Area Network: This applies to multiple small LANs that are connected across multiple buildings within a small area. It’s common to see CANs used to link up multiple buildings of a large company’s head office, a military base, or even a college campus. (Once again, sorry about the artwork)

CAN Topology

Wide Area Network: A WAN is created when 2 or more LANS are connected together across a large geographic area. On a map, a WAN would look like several stars, linked together. The most famous example of a WAN is – of course – the Internet.

CAN Topology

Global Area Network: A GAN is a single giant private network that covers the entire globe. Only extremely large companies use GANs. If you were to look at a GAN on a world map, it would resemble a single giant spider web. This topology makes it very different than a WAN, and more like an extremely large LAN.

LAN topology


Storage Area Network: This one actually DOES NOT belong on this list. I’ve only added it here because many people seem to be confused about the term. Although there are some networking components to a SAN, it should primarily be considered a storage device. Simply put, a SAN is an external storage device that can be used by a server as a primary disk storage. (Much like your C: drive)

There are a number of reasons why you’d want to do this… and I’ll discuss those in a later article. But for now you just need to know that when someone uses the term SAN, they are not talking about networking. They’re talking about STORAGE.

Let’s make this even simpler.

The field of networking is constantly evolving, and new terms come out all the time. But these are the major ones.

Having said that, LAN and WAN are the most commonly used acronyms. They can be usually be substituted for other types of networks without getting into semantics. If you can just remember those two descriptions, you’ll be fine for most discussions.