Segmentation is a memory management technique used in operating systems where a process is divided into segments or blocks of different sizes, each representing a different logical address space. Segments typically correspond to different parts of a program, such as the main function, data structures (like stack and queue), and functions.
In segmentation, the operating system maintains a segment map table that contains crucial information about each segment, such as the available memory blocks, their sizes, segment numbers, and memory locations. This table is used for address translation, allowing the process to access the appropriate segment in the main memory.
Segmentation provides flexibility in memory allocation as segments can grow or shrink dynamically based on the needs of the process. However, it also introduces complications in managing fragmented memory and requires additional overhead in maintaining the segment map table. Careful handling of segment sizes and proper management of segment tables are essential for effective implementation of segmentation in an operating system.