Difference Between Paging And Segmentation

Difference Between Paging And Segmentation in Operating System

A process address space is broken into fixed-sized blocks, which is called pages. A process address space Is broken in differing sized blocks called sections.

Paging: It is generally a memory management technique that allows OS to retrieve processes from secondary storage into main memory. It is a non-contiguous allocation technique that divides each process in the form of pages.

Segmentation: It is generally a memory management technique that divides processes into modules and parts of different sizes. These parts and modules are known as segments that can be allocated to process.

Difference Between Multitasking and Multiprocessing

Paging	Segmentation
A page is of the fixed block size.	A segment is of variable size.
It may lead to internal fragmentation.	It may lead to external fragmentation.
In Paging, the hardware decides the page size.	The segment size is specified by the user.
A process address space is broken into fixed-sized blocks, which is called pages.	A process address space Is broken in differing sized blocks called sections.
The paging technique is faster for memory access.	Segmentation is slower than paging method.
Page table stores the page data	Segmentation table stores the segmentation data.
Paging does not facilitate any sharing of procedures.	Segmentation allows for the sharing of procedures.
Paging fails to distinguish and secure procedures and data separately.	Segmentation can be able to separate secure procedures and data.
In this, OS needs to maintain a free frame.	In this, OS needs to maintain a list of holes in the main memory.
In paging, the type of fragmentation is internal.	In segmentation, the type of fragmentation is external.
The size of the page is determined by available memory.	The size of the page is determined by the user.
It is invisible to a programmer.	It is visible to a programmer.
In this, the size of pages is fixed.	In this, the size of segments is not fixed.