I'm not sure if the people who invented the computer modeled it after the brain, but I often see many similarities between the two.
Everyone knows about short term and long term memory. The short term memory is the one you use to remember phone numbers when told so that you can key them in to your phone. After which, 10 seconds later, you'd have forgotten it totally, or at least most of it. You also use your short term memory for alot of things, like to remember what you intend to do next after the thought of what to do next comes to you. It's short term, because, given a day or two later, you'd probably not remember what exactly happened at that same moment than if asked just a few seconds after the "event".
Computers have a parallel. RAM, or Random Access Memory. Which is why, if you don't save your work, and the power goes out, you lose whatever you had been working on. The computer saves whatever you type, as you type, into the RAM, because it works faster than storing it directly to the harddisk. The comparisons I'm doing however, is purely conceptual, since the RAM requires electricity to run, and loses memory when denied electricity. So, conceptually, the RAM and the short term memory are similar.
Then we have the long term memory. The one that you use when tying your shoelace, or when you ride a bike. It stays in your memory just about forever, as you can't really forget how to tie your shoelace nor how to ride a bike under normal circumstances.
The parallel in the computer is the harddisk. It stores information when you save them, and no matter how many times you turn off or on the computer (theoretically) the information will never be lost. There is harddisk degradation though (i.e. the material degrades), which causes some data to end up corrupted. And the brain is rather similar too! Some old people become senile after a certain age. Cause? Memory degradation.
There is another "medium" term memory, like, the memory you use when you hit the books for a test the next day or two. It's pretty good in remembering stuff for that period of time, but, by a few months later, just about all of it is gone. Doesn't seem like the computer has a parallel to it right? But, in fact the computer has something rather similar. It's called virtual RAM. Because the RAM can only be so big, and also for the reason of optimality, the computer shifts data that is not frequently used, or data that it deduces that will not be used soon, into the harddisk. The data stays in the harddisk for quite some time, until it is written over by more incoming data. This usually happens by chance, just like we remember some facts much longer than others aquired in the same time, around the same time.
Lastly, a common trait that all memories in the computer has is an operating speed. RAM has the fastest speed. It is written to and read from really fast, as it is directly coupled to the processor, and has to match up with the processor so that it would not slow the processor down. This, I suppose can be related to how fast people remember things. Some can remember faster than others, while some take a longer period of time.
Information written to harddisk takes a longer period than information written to the RAM. Likewise, we take a longer period of time to remember stuff longer, while only a second or two to remember stuff for a short period of time.
I suppose that's all there is to for memory, and this ends the first part of the topic.