The term 'segmentation fault' refers to an error that occurs when a program attempts to access an area of memory that is not allocated or protected. This typically happens when the program tries to read or write to a memory location outside its allocated address space, leading to a crash or unexpected behavior. Segmentation faults are common in languages like C and C++, where the programmer must manage memory allocation manually. Debugging tools are often needed to trace these errors back to their source, helping developers ensure the stability of their applications.