What is the difference between the functions memmove() and memcpy()?

 
   void *memmove(void *DST, const void *SRC, size_t LENGTH);

   This  function moves LENGTH characters from the block of memory start-
   ing at `*SRC' to the memory starting at `*DST'.  `memmove'  reproduces
   the characters correctly at `*DST' even if the two areas overlap.

   void* memcpy(void *OUT, const void *IN, size_t N);
 
   This  function  copies N bytes from the memory region pointed to by IN
   to the memory region pointed to by OUT.

    If the regions overlap, the behavior is undefined.