What is a perfect binary tree and how does it differ from other types of binary trees?

A perfect binary tree is a type of binary tree where all levels are completely filled with nodes, except possibly for the last level, which is filled from left to right. This means that every parent node has exactly two children.

In contrast, other types of binary trees may have missing nodes or uneven levels, resulting in a less balanced structure. This can affect the efficiency of certain operations, such as searching and inserting elements, making perfect binary trees more predictable and easier to work with in some cases.