Most of us, or at least I, use the words "router" and "modem" interchangeably without even knowing what they mean. I, for one, didn't even realize they were two separate devices until not that long ago! It turns out that these are two individual devices, each with a slightly different purpose. Together, their work culminates in your internet connection. I think we all knew at least that! Now let's learn the difference between these two devices.
The word modem means modulator-demodulator. You'll understand what that means in a jiffy. It's the part you simply have to have if you want internet in your space. It establishes a connection to your internet service provider so that they can give you access to the internet.
How does it work?
There are 2 different types of signals. While a computer only reads digital signals, the internet only sends and receives analog signals. The modem demodulates analog signals into digital ones and modulates digital signals into analog ones.
Still confused? We get it. Think of it this way: the computer and the internet speak 2 different languages. The modem is their translator!
The two most common types of modems are cable and DSL-type modems. We can go on and on about that, but this video explains and demonstrates everything so well:
This is the second act of the internet show. The router comes after the modem. A router can be large (mostly for commercial use) or small (for home and office use). Both do the same thing.
The router, as its name suggests, routes the internet connection to your devices. It directs the connection your modem establishes continually into every device that connects to the internet. It has several ports so that you can connect to the net via a cable, and it also provides a wireless access point, so that you can connect to the internet via Wi-Fi. Wi-Fi is "the radio signal sent from a wireless router to a nearby device," as Verizon put it.
So, if you only had one device that isn't mobile, like a home computer that isn't ever connected to a printer, you wouldn't need a router! You'd simply connect your computer to the modem via a cable and start surfing the web. The moment you need a wireless connection or want to connect more than one device to the net is when you require a router.