Andrew S. Tanenbaum (OS) Edition 4 Exercise 3 Question 5 (Page No. 254)

Question

What is the difference between a physical address and a virtual address?

Answer 1

Physical address:

• The hardware address of the physical memory is known as the physical address.

Virtual address:

• The pointer for a memory location allowed by the operating system to the process for using it is called the virtual address.
• It refers to a location in the primary memory that can be used by the process freely of other processes.
• It can be possible that the virtual address is the same as the physical address.

• Physical memory space and the virtual memory space are independent of each other.

• Virtual Memory Space is not limited by the size of the physical memory space but is limited by the size of virtual addresses.

• If the virtual memory address and the physical Memory address are different then the mapping is done with the help of the Memory Management Unit (MMU).