What's the difference between reserved and committed memory?

Question

I understand that memory has to be reserved before being committed. And when it\'s reserved, no other process can use it. However reserved memory does not count against ava

Answer 1

Process Virtual Memory (Address Space ) and Actual RAM are both different. you can have 512MB physical RAM but still your process can address 4GB virtual address space(2GB Userspace) Every address in a process can be thought of as either free, reserved, or committed at any given time.

A process begins with all addresses free, meaning they are free to be committed to memory or reserved for future use.Before any free address may be used, it must first be allocated as reserved OR committed. But doesn't need to be reserved in order for it to be committed.

reserving memory means reserving virtaul address space for future purposes. it doesn't associated with Physical RAM (mapped to RAM Addresses).where as committed memory means it will be associated with actual RAM so that you can store data in it.

http://msdn.microsoft.com/en-us/library/ms810627.aspx