Fragmentation
In computer science, fragmentation is a process that occurs when various-sized blocks of data storage are allocated and freed in the course of time. It results in the accumulation of small regions of free storage that are too small to be useful for allocation, even though in sum there may be more than sufficient free space. See defragmentation.Fragmentation occurs both in memory allocation in RAM and in secondary storage devices such as hard drives.
Fragmentation is of two types: Internal and External