Segments logically divide a program into logical entities of Code, Data and Stack each having a specific size of 64K. The segment register holds the upper 16 bits of the starting address of a logical group of memory, called the segment.

The main advantages of using segments are:

• Logical division of program, thus enhancing the overall possible memory use and minimize wastage.
• The addresses that need to be used in programs are relocatable as they are the offsets. Thus, the segmentation supports relocatability.
• Although the size of address is 20 bits, yet only the maximum segment size, that is 16 bits, needs to be kept in instruction, thus reducing instruction length.