The CodeHS video does a great job of introducing you to the code for tuples, but they leave it up to the teacher to introduce you to the concept of tuples itself.
First, what's a tuple? It's one of several ways you can store multiple items in one variable.
Tuple is short for double, triple, quadruple, quintuple, sextuple, septuble, octuple, etc. It can be any length.
So what do you need to know? Don't forget that in computer science we begin counting at 0 (more on that here if you're interested).
See the video below: