You've learned lists and dictionaries. Now I'll show you two more collection types that solve specific problems. Tuples are like lists that can't change. Why would you want that?
Sometimes immutability is exactly what you need. Sets are collections where every element appears exactly once. No duplicates allowed.
This changes lookup from scanning every element to instant. By the end of this section, you'll know when to reach for a tuple, when to use a set, and when lists or dicts are still the better choice.