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I am trying to understand both paradigms of memory management;however, I fail to see the big picture and the difference between both. Paging consists of taking fixed size pages from a secondary to a primary storage in order to do some task requested by a process. Segmentation consists of assigning to each unit in a process an address space, so they are allowed to grow. I don't quiet see how they are related and that's because there are still a lot of holes in my understanding. Can someone fill them up?

itachi_uchiha
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  • Possible duplicate of [What is segmentation and paging in Computer Science?](https://stackoverflow.com/questions/23584055/what-is-segmentation-and-paging-in-computer-science) – Tony Tannous Jun 04 '17 at 09:24
  • Also, a simple search in google will produce plenty on good results. https://www.quora.com/What-is-the-difference-between-paging-and-segment-in-memory-management – Tony Tannous Jun 04 '17 at 09:28
  • Possible duplicate of [Differences or similarities between Segmented paging and Paged segmentation?](https://stackoverflow.com/questions/16643180/differences-or-similarities-between-segmented-paging-and-paged-segmentation) – Ciro Santilli OurBigBook.com Jun 11 '17 at 07:55

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I think you have something confused. One problem you have is that the term "segment" had multiple meanings.

Segmentation is a method of memory management. Memory is managed in segments that are of variable or fixed length, depending upon the processor. Segments originated on 16-bit processors as a means to access more than 64K of memory.

On the PDP-11, programmers used segments to map different memory into the 64K address space. At any given time a process could only access 64K of memory but the memory that made up that 64K could change.

The 8086 and it successors used segments with base registers. Each segment could have 64K (that grew with the processors) but a process could have 4 segments (more in later processors).

Paging allows a process to have a larger address space than there is physical memory available.

The 8086's successors used the kludge of paging on top of segments. However, that bit of ugliness has finally gone away in 64-bit mode.

user3344003
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You got your answer right there, paging relates with fixed size pages in a storage while segmentation deals with units in a page. 'Segments' are objects in the class 'Page'

Bashir Korede
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