Have you ever wondered about the difference between memory, storage, and processor? Some of you might already be familiar with these terms, but many aren’t, and over the years I’ve developed what I think is a pretty tidy metaphor that describes what these different parts of the computer do:
The Workspace Metaphor
First, imagine an office. There’s a small desk and a closet and nothing else (for the purposes of this exercise, there’s no computer on the desk! Shocking!).
Lets say you have a project to work on. For a timely example, we’ll say it’s your taxes. You open up your closet and start rummaging through various boxes, bins, and stacks of paper for the records that you’ve thrown into the closet over the course of the year. You take out a bunch of the things you need and start putting them on your desk so you’ll have them to refer to.
You start working, but you’re finding that you don’t have enough room on your small desk to organize the things you brought out, and you weren’t even able to bring everything that you needed because of how little space you had. So, you go and either get a bigger desk to work on or maybe a folding table so you can lay everything out and be able to find whatever you need at a glance. Now you don’t have to make repeated trips to the closet, and you have everything reachable at a moment’s notice.
You’ve finished your task, and now you start putting all your things back in the closet, trying to figure out where you took each thing out from in the first place. Was this in that shoebox? Was that in the stack of papers on this shelf or that shelf? You put it back in, but you’re not really confident you’d be able to find it again.
Next year, you decide to get a filing cabinet full of carefully-labelled folders. Now you know exactly where everything is, and the process of finding and retrieving everything to lay out on your desk and folding table is far faster than it was last year.
What does this have to do with computers?
In this metaphor, the closet is your storage (hard drive), the desk is your memory (RAM), and you are the processor (CPU).
In simplest terms, the CPU instructs the computer to retrieve data from the storage, and loads that data into memory to work on it (this data could be your files or an application you’re opening). This is because RAM is far faster than hard drives. Your CPU doesn’t have to keep going back and forth to the closet every time it needs to work on that paper, it just looks at it on the desk. Things start to slow down when the RAM gets full and the CPU starts having to rely on the hard drive more, much like your workflow slows if you keep having to walk back and forth to get what you need. If you get more RAM (or a bigger desk), you’ll be able to have more things at-hand, which speeds everything up.
In the metaphor, the closet is a Hard Disk Drive (HDD) and the filing cabinet is a Solid State Drive (SSD). SSDs are an incredible step up in computer performance. They also don’t get defragmented like their HDD cousins. Fragmentation happens when a file is stored on the physical disk but needs to be split up because there’s not enough physical space on the drive platter where the computer wants to save it. So the next time you want that file, the drive needs to spin to all the locations where parts of it have been stored. This is like a messy closet where things have been thrown into it through the year. An SSD can access any data on it with equal speed. It’s as though you’ve sorted and organized all your files into a filing cabinet with a well-kept labeling system.
Lastly, you are the processor/CPU. You are the one who is taking the data that’s pulled out and using/manipulating it to create new data. And much like the vast majority of computers out there, it’s almost impossible to upgrade or replace the processor!