A tuple is an ordered collection of items, just like a list. The difference? Once you create a tuple, you can't change it. No adding, removing, or modifying elements.
Think of a tuple as a read-only list. You can look at the values, iterate through them, and access them by index. But you can't alter them. Why would you want this restriction? Sometimes data shouldn't change.
Coordinates stay fixed. Days of the week don't change. When you use a tuple, you're telling Python (and other programmers) that this data is meant to stay constant.