Page and page file

A page is a contiguous of block of 4 kb and so what is page file? how it is 开发者_StackOverflowused by 32 bit processes?

Most processors these days support a concept called "virtual memory", which lets programs act like there's more memory than is physically in the computer. When that "memory" is accessed, the operating system gets a corresponding page from storage somewhere, and sets things up so it looks like it's always been there...and the program is none the wiser. This sometimes involves putting other pages out to storage, since as i mentioned, we're pretending there's more memory than there is -- so the programs that are actually doing something are the ones using physical RAM, and the slackers get pushed out to storage til they decide to do something.

A page file is where those pages are stored in Windows when they're not in use. It's also called a "swap file" in some OSes.