Typical modern software systems allocate memory dynamically from structures known as heaps.
Calls are made to heap-management routines to allocate and free memory.
Heap management involves some computation time and can be a performance issue.
Chunking refers to strategies for improving performance by using special knowledge of a situation to aggregate related memory-allocation requests.
It refers to a facility that allows inconveniently large messages to be broken into conveniently-sized smaller "chunks".