What is a stack overflow?

A stack overflow occurs when a program attempts to use more stack memory than what has been allocated to it. The stack is a region of memory that stores temporary variables created by functions. Each time a function is called, a new block of memory is reserved on the stack to hold its local variables, parameters, and return address. When too many functions are called, or when there is excessive recursion, the stack can become full. This leads to a stack overflow, which typically results in a runtime error or crashes the program.

The other answers presented do not accurately describe a stack overflow. Methods for memory allocation, errors in heap memory, and data compression techniques are all distinct concepts unrelated to the fundamental definition of stack overflow, which specifically pertains to the misuse or overuse of stack memory within a program's execution context.