Segmentation Fault (Segfault)
Definition - What does Segmentation Fault (Segfault) mean?
A segmentation fault (segfault) is an error returned by hardware with memory protection that tells the operating system that a memory access violation has occurred. The operating system usually reacts by telling the offending process about the error through a signal and then the OS performs some sort of corrective action. This happens because a process or program tries to access memory that is not assigned to it.
A segmentation fault is also known as an access violation.
Techopedia explains Segmentation Fault (Segfault)
Segfaults can also be caused by a recursive function, which can use up all of the stack space it is assigned and quickly encroach on memory not assigned to it. In some systems, this is considered a stack overflow, but for others it is simply a kind of access violation.
A segmentation fault can be handled by a process through a custom signal handler, but often it is the OS's default signal handler that is used, which usually results in the offending process being terminated abnormally, called a crash, or the OS forcing a core dump.