In the recent era of computing, applications and operating systems cannot survive without efficient memory management, especially if an application has to be under survey load for an undefined long time. Efficient utilization of resources will enhance performance. This paper describes the memory management in an operating system and it will demonstrate basic architecture of segmentation in an operating system and basic of its allocation. This paper also describes the basic concept of virtual and dynamic memory management and also review the languages used in system programming such as, C++, java, .NET and assembly languages exploring their issues and techniques in memory management.