Define compactions.

- Compaction is a process in which the free space is collected in a large memory chunk to make some space available for processes.

- In memory management, swapping creates multiple fragments in the memory because of the processes moving in and out.

- Compaction refers to combining all the empty spaces together and processes.

- Compaction helps to solve the problem of fragmentation, but it requires too much of CPU time.

- It moves all the occupied areas of store to one end and leaves one large free space for incoming jobs, instead of numerous small ones.

- In compaction, the system also maintains relocation information and it must be performed on each new allocation of job to the memory or completion of job from memory.