Source : Free On-Line Dictionary of Computing

malloc
     
        {C}'s standard library routine for storage allocation.  It
        takes the number of bytes required and returns a pointer to a
        block of that size.  Storage is allocated from a heap which
        lies after the end of the program and data areas.  Memory
        allocated with malloc must be freed explicitly using the
        "free" routine before it can be re-used.
     
        {gc} is a storage allocator with {garbage collection} that is
        intended to be used as a plug-in replacement for malloc.