So when most of you think about memory, I’m sure one of the first things that pops into your head is that game you played as a kid where you had to flip over cards and find two cards that matched. One of the implementations that I always remember is in the form of a little mini-game in Super Mario Bros. 3:
But that is not the kind of memory that I want to talk about today. Today we will be discussing computer memory. Now that phrase covers a pretty wide berth of things these days and there are a few misconceptions about what memory technically is. We will discuss what memory is, and how it’s used in a bit. First lets understand why we need memory at all.
If you look at everything little thing that happens in a computer from the moment you turn it on to when you power it down, it can all be broken down into little ones and zeros that are called bits. Basically each 0 and 1 represent the flow of electrical current (0 being off and 1 being on). These bits are then stored in small chunks that are called bytes and these bytes are what make everything that happens on your computer possible. And in order for the computer to have ready access to the trillions and trillions of bytes necessary to make a computer function, they have to be stored in some kind of memory. All that data is stored in a few places on your computer but the main memory is what is know as the computers RAM.
Now some of you might connect the word memory with your hard drive but technically that is false and one of the biggest misconceptions about computer memory. You hard drive is considered computer storage not memory. It’s basically a big file cabinet whereas the RAM is where the computer stores programs, applications, and data that it needs to be readily accessible. RAM stands for Random Access Memory and the more your computer has, the faster it will access data and the more programs it will be able to run simultaneously without slowing down. It is also called Random Access Memory because it can be accessed randomly which differentiates it again from the hard drive. The data on the hard drive has to be accessed sequentially whereas RAM can access data from any point. That is what makes it work so much faster than a hard drive and makes it the preferable solution for fast data storage and access.
Another thing that is different between the hard drive and the RAM is their data retention. The hard drive stores the data that is placed on it indefinitely (assuming it doesn’t fail) whereas the data on the RAM is erased every time that you shut down the computer. Another name for memory of this type is volatile memory.
RAM is normally divided into two different sections, physical memory and virtual memory. The physical memory is the typical number that is associated with RAM on your computer when you look at the specs (my computer for instance has 16 Gigabytes of RAM) The RAM also interacts with a small portion of your hard drive which is considered Virtual Memory. This virtual memory serves as a kind of buffer for the physical RAM. Everything that you computer needs to access can’t be stored on the physical RAM so a small portion of space is allocated on your hard drive to store lesser used data that can be quickly reloaded onto the physical RAM when it is needed.
Well that was a brief and somewhat rudimentary look into computer memory that I RAMed into your brain but hopefully I helped make things a little more clear and the next time you think about computer memory, it will be a little easier to remember (Get it….)