The purpose of Memory Management Unit (MMU) is to convert the logical address into the physical address. The logical
address is the address generated by the CPU for every page while the physical address is the actual address of the frame
where each page will be stored.

When a page is to be accessed by the CPU by using the logical address, the operating system needs to obtain the physical
address to access that page physically.

The logical address has two parts.

1. Page Number
2. Offset

Memory management unit of the OS needs to convert the page number to the frame number.

Example

Considering the above image, let’s say that the CPU demands 10th word of the 4th page of process P3. Since the page number 4 of process P1 gets stored at frame number 9 therefore the 10th word of 9th frame will be returned as the physical address.