What are Pages and Frames? What is the basic method of Segmentation?

Pages and Frames:

In the context of computer systems, pages and frames are related to the concept of memory management, specifically in a technique called paging.

1. Pages: When a process is to be executed, its size is evaluated and then it is divided into blocks of fixed size. These blocks are called pages. The size of a page is defined by the system architecture. The division of a process into pages is performed by the operating system.

2. Frames: The physical memory in a computer system is also divided into fixed size blocks. These blocks are called frames. The size of a frame is the same as the size of a page. When a process is to be executed, its pages are loaded into the available frames in the main memory.

Segmentation:

Segmentation is another method of memory management used in computer systems. Here's the basic method of segmentation:

1. Unlike paging, segmentation divides the process into segments based on the logical division rather than fixed size division. A segment could be a function, a data structure, etc.

2. Each segment is loaded into the main memory whenever it is needed for execution. The segments can be of varying sizes and they do not necessarily occupy contiguous locations in memory.

3. Each segment has a specific name and can be referred to it directly. This is different from paging where the pages are anonymous and can only be referred to indirectly through a page table.

4. Segmentation allows for better utilization of memory as it reduces external fragmentation. However, it can lead to internal fragmentation if the segments are not fully utilized.

5. Segmentation also provides protection and sharing mechanism. Different segments can have different levels of protection (like read-only, execute-only) and some segments can be shared among processes.