MIN

• Replace the cache entry that will not be used for the
  longest time into the future
• Optimality proof based on exchange: if evict an entry
  used sooner, that will trigger an earlier cache miss

Least Recently Used (LRU)

• Replace the cache entry that has not been used for
  the longest time in the past
• Approximation of MIN

Least Frequently Used (LFU)

• Replace the cache entry used the least often (in the
  recent past)