Memory Leak
In plain terms
Memory that a program allocates but never releases, slowly exhausting it.
Going deeper
When code keeps references to memory it no longer needs, that memory is never reclaimed, causing usage to grow until the app slows or crashes. Leaks are common in long-running services.
Under the hood
In GC languages, leaks come from lingering references (caches, listeners, closures), not missing frees; profilers and heap dumps locate them.
Examples
Unremoved event listeners, growing caches, unclosed resources, C malloc without free.
Think of it like...
Like checking out library books and never returning them: eventually the shelves empty and no one else can borrow.