NRU (Not Recently Used) – it searchs the pages that had not been referenciadas in the last accesses to be substituted. Such information is kept through a bit. The algorithm also verifies, through an modification bit, if the page had its content modified during its permanence in memory. LFU (Least Frequently Used)? algorithm that less chooses the had access page amongst that they are in the memory. For this, an accountant of accesses associated to each page is kept so that if he can carry through this verification. This information is zeroed each time that the page leaves the memory, harming the just-loaded pages, a time that for being with the accountant of accesses zeroed the probability to be substituted is bigger.

MFU (Most Frequently Used) – opposing of the LFU, therefore substitutes the page referenciada. The control is made by access accountants, being that the biggest problem is to ignore the beginning of secular locality. WS (Working Set) – algorithm that possesss the same politics of the LRU, with the difference that this does not carry through only the substitution of pages, it establishes a maximum time for each one in the memory. Thus, all page that has its depleted time is removed of the memory, having left the number of active pages changeable. Segmentation Segmentation is a procedure of the management of memory, where the programs are divided in sub-routines and structures of data, and later they are placed block-type of information in the memory that possess different sizes with its proper space of addressing. The difference between the paging and the segmentation is that, the first one divides the program in parts of so great fixture, without any linking with the structure of the program, already as it allows a relation enters the logic of the program and its division in the memory. The mapping mechanism is very similar to the one of the paging, with the table use of segments.

Beyond the address of the segment in the physical memory, each entrance in the table possesss information on the size of the segment and if it is or not in the memory. The operational system keeps a table with the free and busy areas of the memory. When a new process is loaded for the memory, the system locates a free space accomodates that it. In the segmentation the referenciados segments are only transferred of the HD to the memory. BIBLIOGRAPHICAL REFERENCE De Internet: BRUNO.