There are TWO kinds of memory your computer uses:

1) RAM - This is short for Random Access Memory. Your computer uses RAM to open and run various programs. The more RAM your computer has, the more things it can do at the same time.

2) Hard Disk Memory - This is the memory that is available for you to save your work.

Have you ever gotten a message saying "Not enough memory to complete that operation" or "Type 1 Error"? That's because your computer ran out of RAM to open another application. This occurs when you have several programs running at the same time.

For example, you are currently online using Internet Explorer, have Microsoft Word open because you're working on a document, have Adobe Acrobat open to view online instructions, AND you want to check your mail using Outlook Express. That's a lot of things going on at the same time! If your computer does not have a lot of RAM installed (say, 32MB or 64MB) then it's going to slow down or crash because it's trying to do more than its memory will allow. If you QUIT some applications, then you should be able to open others.

So how do I find out how much memory is installed on my computer?

Once again, there are TWO ways to do this (Are you detecting a pattern here? There are at least two ways to do almost everything on a computer!)

1) Go "Under the Apple" and select "About This Computer" just like you did in Lesson 1. Only this time, take note of the Memory readings.

Here is the way your computer looks right after starting up. There are no applications currently open.

(It looks like this computer has quite a bit of RAM installed! That's because I added 256MB to the 128MB that came with this iMac.)

Look below and notice how the RAM changes when applications are open.

As you can see, the more RAM you have installed on your machine, the more things you can do simultaneously. Fortunately, installing RAM is easy and inexpensive. The price of RAM cards are going down. As a general rule, your computer should have at least 64MB of RAM installed to run smoothly. You can always buy some more to upgrade your system.

2) Look at the Apple System Profiler to see how much memory is available.

Go "Under the Apple" and select "Apple System Profiler."

The Apple System Profiler window will open, shown below:

Not only will The Apple System Profiler show how much memory is available, it tells you EVERYTHING about your computer!

The Apple System Profiler is especially handy when you need technical support, since this information is critical to tech support people in order to help solve your problem.

All computers running OS X must have at least 128MB of RAM in order to be installed. Check the memory currently installed on the computer you're using right now. Go ahead...I'll wait.

How much was installed? Is it enough? Check the computers in your classroom and see how much memory is installed on each. You may be surprised!

Watch a movie about RAM! CLICK HERE! (:55)

Now that you have an understanding of RAM, let's go to Lesson 2B: Hard Disk Memory.