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!
Modem types
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:
