What’s a modem? What’s a router? Why does it matter when the Wi-Fi keeps going down? Don’t get your Ethernet cables in a tangle! America’s digital goddess is here to help with some simple explanations for all that frustrating language.

Your home network

Before we talk about modems, we need to talk about networks. People used to just have a single family computer in the living room for internet access. That may still be the case, but everything wants out on the web these days. Everyone may have laptops and tablets, then smartphones all need an internet connection, even the TV needs a way to talk to the cable company if you want to watch your shows. You might even have a smart speaker like Alexa or Google Home that helps make life easier. Whether you know it or not, you have a network.

The network of networks

If your home network wants to connect to all the other networks out there — be it your best friend across the country or your streaming provider so you can watch movies — they all have to be speaking the same language, and those requests and information all have to get from place to place. The internet is just a network of networks talking to each other.

What does a modem do?

Your modem is the pathway for all your devices to speak with networks across the world. When you tell Netflix you want to start a movie, or your toddler wants to see the next YouTube video, that device sends out a request. “Modem” means “modulator-demodulator.” It sounds pretty Star Trek, but what it does isn’t so space age. A modem takes that request to play a movie or watch a video and translates it into signals that can travel across the wires that connect your house to your internet provider, and from there into the wider world. Once the answers or information comes back to your house — “Okay, here’s the movie!” — something has to translate it from signals that can cross a wire back into that romantic comedy you’re finally getting to watch.

So what about routers?

However, the journey doesn’t end there. Once the data arrives and your modem decodes it, it has to get where it’s going. There are usually many different streams with lots of different information, so you want to watch Mamma Mia, but your son is trying to do homework and your daughter is playing Fortnite. If his Social Studies pops up where your Abba songs should be, things are going to get tense. That’s where routers come in. A router sends the incoming data where it needs to go and keeps track of which stream of data goes where. It’s the traffic cop that keeps everyone from finding out about your secret love of musicals or keeps everyone from being subjected to a long lecture on the War of 1812. Routers also handle a lot of the work of managing your home network. They do things like run the Wi-Fi connections, use a firewall to keep out hackers, and manage the quality of service, so your movie stays in high definition even when someone else is downloading more homework. Many internet providers nowadays use a box that combines both functions. The wire from your wall might go to a combination modem and router, which decodes the traffic and sends it where it needs to go without you having to lift a finger. Sometimes, technology is amazing. At least until the Wi-Fi goes down.