What’s the difference between “C’est” and “Il est”?

An man in a button-down shirt holds up his hands in confusion.

When you first learn French, it seems easy: C’est means “It is/It’s” or “That is/That’s”, and Il est or Elle est means “He is/He’s” or “She is/She’s” (or “It is/It’s” if the “It” is an object, animal, etc.). But pretty soon, you’ll probably notice something strange. At times, c’est and il est seem to be …