abort() is a Utility Function that abort(terminate) the program execution immediately. It will return an implementation defined value to the calling process, in environments that support this function otherwise never returns to the calling program.

    void abort(void);

   #include <stdlib.h>
   #include <stdio.h>
   int main()
     {
       printf("The program will get aborted");
       abort();
     }

   The program will get aborted
   Abnormal program termination

In the above example abort() terminates the program and returns an implementation defined value.