[Theodores]

Perhaps it would clarify things with analogy:

Let's say Bubba's watching the Super Bowl. The table in front of him are his registers, the fridge is cache, and the corner shop a quick walk away is memory.

He looks and see he doesn't have any beer on the table. So he goes to the fridge and gets what he wants, and comes back to the couch. Later, Bubba runs out of beer (useful data). This is a cache miss, so he has to go down to the corner store and get some beer. Instead of just getting what he wants, maybe he gets some Hungry-Man frozen dinners, in case he'll want some later. He goes back, puts the beer and TV dinner in the fridge, and brings some beers with him to the table. Next time he runs out of beer, he goes to the corner store, but they're all out of beer. So he buys some seed, tills the fields, and grows his own barley. This is disk access.

http://ucb.class.cs61c.narkive.com/pKzt4z6G/the-doe-library-...

[terrymah]

Hmph. You forgot the part where Bubba's friends are watching him drink beer and eat Hungry-Mans, and if they want some, they can force Bubba to throw out all his food and pour all his beer down the drain, and everyone has to go back to the store.