• The placement policy is the set of rules that determines where the virtual page is loaded in memory. If memory isn’t full, the VM Manager selects the first page frame from a list of free page frames. This list is called the page frame database, and is an array of entries numbered from 0 through n _ 1, with n equaling the number of page frames of memory in the system. Each entry contains information about the corresponding page frame, which can be in one of six states at any given time: valid, zeroed, free, standby, modified, or bad. Valid and modified page frames are those currently in use. Those zeroed, free, or on standby represent available page frames; bad frames can’t be used.