Introduction - If you have any usage issues, please Google them yourself
Piece of virtual memory in the virtual space of the program segment can accommodate a few more main memory space to store the same program segment length of a few to many more. Therefore, when bound to all the pages in main memory are occupied, or all of main memory space occupied, and re-transferred from the disk storage a new page (or above) the situation. At this time, must be eliminated from the main memory in a common page (or procedures) to free up main memory space to store the new page transferred (or program segment), then what kind of rules in accordance with the replacement of the main memory page (or program segment) it? This is the page replacement algorithm to solve the problem.