least frequently used (cache) (LFU)
Least Frequently Used (LFU) is a cache algorithm that determines and replaces the least frequently used memory block of a buffer memory.
This displacement strategy is used in caches, controllers and virtual memory management and displaces the least read entry. The LFU method does not store complete timestamps, but only a few bits. These mark in which frequency a file was called.
Other displacement strategies are Least Recently Used( LRU) and Most Recently Used( MRU).