• In segmentation a program data and instruction are divided into block called segments, A segment is a logical entity in a program.

• Programmer's view of segment is as follow:

Physical view:

• It consist of non-adjacent of memory allocated to segments.

• All segments size may or may not be equal and segment can be implemented with or without paging.

• Collection of segment is called as logical addr space.

• Each segment is identified by its name.

• Processor generates logical address, these addresses consist of segment number and an effect in the segment and segment number is used as index to segment page table.

• Operating system maintain a segment table for each process. it is usually stored in main memory as a segment that in net to be loaded as long as the process can run.

• Each entry in the segment table has a segment base and segment limit.

• the base contains the segment relocation register for the target segment.

• The segment limit field contains the length of the segment.

• Segment table contains the physical address of the start of segment then add the offset to the base and generates the physical address.