The handling or management of primary memory and back and forth movement of processes between main memory and disk during execution is the functionality of operating system. This is called Memory Management. Regardless to its allocation to some process or not each and every memory location’s record track is kept by memory management. How much memory has to be allocated to process is checked and decision of giving memory at particular time is taken by it. Memory management updates its status whenever some memory is freed or not allocated. This chapter will discuss basic concepts related to memory management.