LFU Least Frequently Used Records the number of accesses and deletes the Least number of times
FIFO First in First out queue implementation
The principle of LRU Least Recently Used seems a little difficult to understand. We should consider both the most recent and the Least.
Implementation on access only records Boolean values. Sort the queue by recent access. Exists: delete, put to the front of queue Does not exist: put to the front of queue, delete the last one if it is full