Fragmentation issues usually refer to problems primarily faced by the internal implementation of the memory allocation engine itself, and not so much by the typical application developer. Fragmentation issues are usually of two types: internal and external.
External fragmentation usually refers to the situation where, after several days of uptime, even if the free memory on the system is, say, 100 MB, the physically contiguous free memory might be less than a megabyte. Thus, with processes taking and releasing various sized memory chunks, memory has become fragmented.
Internal fragmentation usually refers to the wastage of memory caused by using an inefficient allocation strategy; often though, this cannot be helped, since wastage ...
