Home networking explained, part 1: Here’s the URL for you – CNET

Editors’ note: This story was originally published on December 9, 2014, and has been updated with additional information.

Do you know that Wi-Fi and Internet are two different things? That’s true, Wi-Fi is just a wireless method for devices in a local network to connect to one another using a router and share a single Internet connection, if there’s one. Then what is a local network, you ask? And what’s a router for Pete’s sake?

Well, if you’re having a hard time with these basic terms, you’re reading the right post. Here I will (try to) explain them all so that you can have a better understanding of your home network and hopefully a better control of your online life. There’s a lot to explain so this is just the first post of an evolving series.

Advanced and experienced users likely won’t need this, but for the rest, I’d recommend reading the whole thing. So take your time, but in case you want to jump to a quick answer, feel free to search for what you want to know and chances are you will find it within this post.

1. Wired networking

A wired local network is basically a group of devices connected to one another using network cables, more often than not with the help of a router, which brings us to the very first thing you should know about your network.

Router: This is the central device of a home network into which you can plug one end of a network cable. The other end of the cable goes into a networking device that has a network port. If you want to add more network devices to a router, you’ll need more cables and more ports on the router. These ports, both on the router and on the end devices, are called Local Area Network (LAN) ports. They are also known as RJ45 ports. The moment you plug a device into a router, you have yourself a wired network. Networking devices that come with an RJ45 network port are called Ethernet-ready devices. More on this below.

Note: Technically, you can skip the router and connect two computers directly together using one network cable to form a network of two. However, this requires manually configuring the IP addresses, or using a special crossover cable, for the connection to work. You don’t really want to do that.

The back of a typical router; the WAN (Internet) port is clearly distinguished from the LANs.

Dong Ngo/CNET

LAN ports: A home router usually has four LAN ports, meaning that, straight out of the box, it can host a network of up to four wired networking devices. If you want to have a larger network, you will need to resort to a switch (or a hub), which adds more LAN ports to the router. Generally a home router can connect up to about 250 networking devices, and the majority of homes and even small businesses don’t need more than that.

There are currently two main speed standards for LAN ports: Ethernet (also called Fast Ethernet,) which caps at 100Mbps (or about 13MBps), and Gigabit Ethernet, which caps at 1Gbps (or about 150MBps). In other words, it takes about a minute to transfer a CD’s worth of data (around 700MB or about 250 digital songs) over an Ethernet connection. With Gigabit Ethernet, the same job takes just about five seconds. In real life, the average speed of an Ethernet connection is about 8MBps, and of a Gigabit Ethernet connection is somewhere between 45 and 100MBps. The actual speed of a network connection depends on many factors, such as the end devices being used, the quality of the cable and the amount of traffic.

Home networking explained

• Part 2: Optimizing your Wi-Fi network
• Part 3: Taking control of your wires
• Part 4: Wi-Fi vs. Internet
• Part 5: Home router setup
• Part 6: Securing your network
• Part 7: Powerline explained
• Part 8: Cable modem shopping tips
• Part 9: How to access your home computer remotely