What does the list method append() do?

The method append() is a built-in function in Python specifically designed for lists. Its primary role is to add a new item to the end of the list. When you call this method and pass an argument to it, that argument is added as the last element of the existing list, modifying the original list in place. For instance, if you have a list like [1, 2, 3], and you use append(4), the list becomes [1, 2, 3, 4].

This functionality is essential for dynamically modifying lists during program execution, as it allows programmers to build collections of items easily without needing to know the list's current size or maintain indices.