leaky abstraction

Leaky abstraction is when something that looks simple on the outside can have more complicated parts inside it. It's like having a pool with a big blanket on top of it. The blanket looks like it would be enough to keep the water in the pool, but if you take a closer look, there might be some holes in the blanket that allow some of the water to leak out of the pool. Leaky abstraction works in the same way, where something that looks like it would be easy to use might have some hidden details or complexities that you don't see at first.