Memory management is one of the main functions of an operating system. This video is an overview of the paged and segmented memory management systems. It describes how a segmented memory management system employs segments of different sizes, which can result in fragmented free space and prevent large processes from accessing the memory very often. This is compared with a paged memory management system in which small equal sized pages are used instead. Concepts such as logical and physical memory are explained, as well as the use of secondary storage to provide virtual memory.