What is memory?
A little of history
These days, no matter how much memory your computer has, it never seems to be quite enough. Not long ago, it was unheard of for a PC (Personal Computer), to have more than 1 or 2 MB (Megabytes) of memory. Today, most systems require 128MB to run basic applications. And up to 512MB or more is needed for optimal performance when using graphical and multimedia programs.
As an indication of how much things have changed over the past two decades, consider this: in 1981, referring to computer memory, Bill Gates said, "640K (roughly 1/2 of a megabyte) ought to be enough for anybody."
What is memory?
Memory is the main place where your computer stores and reads information while it is running. That's part of the OS and software you're running and also data he's working with.
The main difference between memory and your harddrive is that memory is a pure electronic device and you can access every part of it in very short time by just sending the adress where you want to put/get your data. Memory is a temporary storage as it only works as long as it has power. If you shut off the power every information in it is lost.
Why is it so important?
Memory is important because it's what keeps your computer running quickly. When you have a lot of programs running, they may consume all your memory. When this happens, your computer has to use your hard disk for memory. Because hard disks are almost a hundred times slower than memory, your computer slows to a crawl when it runs out of memory. It also often becomes unstable.
