Take a look at the back of any router or other networking gear, and you'll see a row of seemingly identical RJ45 ports. However, these ports are not always interchangeable — you'll typically find one or two ports labelled WAN, while the others may be numbered or marked LAN. Even though they may look the same and even use the same Ethernet cables, these two types of ports serve completely different purposes.

The distinction between WAN and LAN matters the most when you're setting up a new router or adding new devices to your network. Many devices like TVs, gaming consoles and PCs benefit from a wired link to your network for faster download speeds and connection stability. But if you accidentally plug one of these devices into the wrong port on your router, it may not be able to access the internet.

The WAN port on your networking gear acts as the gateway to the internet, while LAN ports connect devices within your local network and allow them to communicate with each other. LAN stands for Local Area Network, and refers to the network created entirely within your home or local environment. On the other hand, WAN is short for Wide Area Network and serves as the physical link to the outside world, typically the internet.

Wi-Fi is effectively another way of connecting your devices to your local network, or LAN. But instead of physically plugging in an Ethernet cable, Wi-Fi allows devices to wirelessly communicate with your router. Many modern routers allow you to create a guest Wi-Fi login that creates a secondary local network or LAN, which is a useful security measure.