<h2><em><u>Demand</u></em><em><u> </u></em><em><u>paging</u></em><em><u> </u></em><em><u>:</u></em></h2><h3><em>In computer operating systems, demand paging (as opposed to anticipatory paging) is a method of virtual memory management. In a system that uses demand paging, the operating system copies a disk page into physical memory only if an attempt is made to access it and that page is not already in memory (i.e., if a page fault occurs). It follows that a process begins execution with none of its pages in physical memory, and many page faults will occur until most of a process's working set of pages are located in physical memory. This is an example of a lazy loading technique.</em></h3><h3 />
