Why Abort signal from abort(3) (SIGABRT) code example

Example: Runtime Error: Runtime ErrorAbort signal from abort(3) (SIGABRT)

SIGABRT –
If an error itself is detected by the program then this signal 
is generated using call to abort(). This signal is also used by
standard library to report an internal error. assert() function
in c++ also uses abort() to generate this signal.