Memory management is very essential feature of an operating system which manages primary memory. Memory management keeps into account each and every aspect of memory location when it is allocated to some process or when it is free. It checks the amount of memory to be allocated for further process. It decides which process will get memory at what time.

An address which is generated by CPU is a logical address whereas address by default, available on memory unit is a physical address. Logical address is also called Virtual address.

Swapping
It a mechanism which swaps a process temporarily out of main memory to a backing store , and then brought it back to the memory for continued execution.
Transfer time is the Major time consuming part of swapping . Total transfer time is directly proportional to the amount of memory swapped.

Segmentation
Technique to break memory into logical pieces is called Segmentation. Each piece represents a group of related information.