The most basic three-way switch setup has two switches that connect and control one light ... Take a look at these two diagrams below. The first is an outline of what you should see.

A 3-way switch adds two terminals for travelers, which connect two 3-way switches together. Yes. Just use the common terminal and one of the traveler terminals for the incoming and outgoing power ...

In the diagram on the link they are using a three conductor cable ... On the far end 3 way switch, black was common, and red was the traveler connecting the two three way switches.

Or flip a switch at the bottom of the stairs, and then again at the top. The next person, coming from either direction, must be able to turn the light on again. That’s where 3-way switches come in.