Image a nice, modern restaurant kitchen with a work table in the middle where the chef does his work. The size of that table determines how much work the chef can do at any one time. Around the room are lots and lots of cupboards and shelves. In those cupboards are stored supplies for anything the chef may want to make. The chef also sometimes puts things on the shelves temporarily if the work table is too small.
In computer terms, the work table is the RAM. Computers today often have a "work table" about 1GB or 2GB (1000-2000MB) in size. If your computer has 256MB or 512MB of RAM, then the chef in your computer is being forced to work on a small work table. Giving him a bigger table would make the chef's work easier and quicker.
The shelves around the room represent the memory in your hard drive. The number and size of the shelves doesn't really affect how much work the chef can do, or how fast he can do it. However, if there aren't very many shelves, they may fill up quickly! New computers today (Jan 2009) often come with 100 or 200GB of space. You can even add on extra drives today that have 1000GB of space. If your computer is older, you may have only 40 or 20GB (or less!) of space. If you start copying pictures to your computer from a digital camera, then those shelves may be getting quite full!
When you turn your computer off, the work table is automatically scrubbed washed clean. When your computers starts again, it has a fresh table to work on! However, the shelves are not affected at all when your computer is off.
When shutting the computer down, most computers have a "Sleep" option and a "Hibernate" option. What's the difference?
Well, with "Sleep" mode, the lights in the kitchen are turned off, and the chefs freeze in mid-stride, exactly where they are! As long as the computer has electricity available, it can keep the chefs frozen and the work table full of what they were working on. When you turn the computer "on" again, the light is turned on and the chefs happily carry on, hardly knowing that anything had happened! If the electricity is interrupted or the batteries use up their charge, then the "sleep" is gone, and the work table is cleaned off, ready to start again from the beginning.
With the "Hibernate" mode, before it shuts down, a copy of everything on the work table is made and put on a nearby shelf. It doesn't need any electricity to keep it on the shelf, so it can stay like this for as long as you want. When the computer is turned back on, the contents of that shelf are copied back to the work table, and the chefs can pick up from where they left off. This is the more ecologic option, and safer for laptops that have limited battery life!
Those shelves do have potential problems however: how does the chef find things on them? And if there isn't a big enough space available when he needs to store a big file, he may break the file up and put parts of it on different shelves! In itself, this is not a serious problem, but when you want the file again, the chef could be quite busy finding all those parts for you! Windows has a tool that can help fix this problem by "defragmenting" the shelves, rearranging and organizing the contents so that big files can be put back together.
Over the years, the chefs (CPU) in our home computers have been getting faster and faster! In the 1990's, the chef could move at, say, 100 recipes a second. Lately, the newest chefs can move at 3,000 recipes a second. Just a little faster, wouldn't you think!! And it gets even better, because Intel and AMD have figured out how to clone the chef and get 2 or 4 into one computer. So now, the work table is shared by a number of very fast chefs!
These fast chefs sometimes get frustrated when getting things from the shelves, because the doors on the shelves can only be opened and closed so fast. If the shelves are too slow, then even the fastest chef will have to go slow!
In our kitchen, there is a serving window out to the rest of the restaurant. That's the computer screen. The "size" of the window is measured in dots (pixels)... how many dots across and how many dots high. In the 1990's, most screens could show about 1000 dots across and 700 dots high. Today, laptops often show 1400 dots across and 900 dots high. (These dots may be different sizes, so the same number of dots may result in, for example, a 14", 15" or 17" physical size.)
And what can be done with that window has also increased dramatically. If you want to play advanced games, then the screen has to do lots of work! Originally, the chef(s) in the computer had to worry about many of the advanced details, and that kept them quite busy! But today, with hardware from NVidia, Radeon, ATI, and so on, a couple of very fast chefs who just look after the serving window can be added. If your computer doesn't have such a special video card, then you may not be able to play some of the most demanding games!
So what can be changed on your older computer?
Enlarging the work table is usually quite effective, easy and not too costly. Buy some more RAM. (But make sure it will fit in your computer! There are lots of different models.)
However, even with a larger work table, a slow chef is still a slow chef. And upgrading the chef (CPU) in your computer is not very simple since the rest of the kitchen may not match his expectations! Usually it is easier to simply buy a newer computer and get a faster chef and utensils he knows how to use...
If you are running out of shelf space, adding more hard drives can reduce the congestion and give you lots more room. But be sure the hard drive is a fast one, or the chef will be forever waiting for the doors to be opened and closed. If needed, the contents of the old shelves can be copied over onto the new shelves.
And if you want to have nice graphics (for games or for Vista's Aero display), then you'll need a video card to supply those chefs that can specialize in making the display work great!
