Segmentation is an additional overhead which relates to the sharing of logical memory between processes. The page overhead relates to the mapping of logical to physical addresses. A segment is a convenient block of logical memory which is assigned to a process when it is executed. The memory given to any process is divided up into one or more segments which then belong to that process. The purpose of segments is to help the system administrate the needs of all processes according to a simple paradigm. Each segment of memory is administrated separately and all of the checks on valid addressing are made on each segment