# Memory segment

A memory segment is a variable-sized block of memory used in segmentation , an alternative to paging for memory management. Instead of dividing memory into fixed-size pages , segmentation divides memory into logically distinct sections, such as code, data, and stack segments. Each segment has a base address and a limit, defining its size and boundaries. The operating system and the Memory Management Unit (MMU) manage segment access using a segment table , which maps segment numbers to physical memory . Unlike paging , segmentation allows programs to organize memory based on logical structures rather than fixed-size blocks.