metaphorical.ly

A Cache is a Brain

The brain is similar to a cache in the sense that it is capable of retaining information extracted from some other source. The source of that information is called the system of record, which is typically slower to access, so our brain keeps a copy of the record for the express purpose of accessing the information in a more rapid fashion.

Consider the number stored on your mobile phone, the system of record. Most of us retain that number in our brain because we typically reference it on such a frequent basis. The value of caching (in the brain) that information is the covenience of rapid recall. Yet, if our brains were unable to store the number, then recollection would be an expensive operation, as it would require thumbing through a sequence of actions on our phone for each and every inquiry.

A cache is usually limited in its capacity to store information, similar to our brain. Typically, the most relevant or frequently accessed information is tucked away for future recall, whereas less important and infrequently referenced information is forgotten. A cache hit occurs when our brain recalls a bit of information and a cache miss happens when something is forgotten.