Ever have one of those backpacker meals? The type that are super lightweight because all the water has been sucked out of them? When you finally sit down at the end of a long hike you simply add water and heat and presto! Meat loaf! Or something that kind of looks, feels and tastes like it.

That's what Zip files are like (only better).

All computer files, just like meat loaf, have stuff in them that can be taken out to make them "lighter." In the case of computer files, taking stuff out of them actually makes them smaller in size, not lighter. Smaller means they take up less space on your computer, but even more important, smaller means easier and quicker to send over the Internet.

But what's the stuff they take out of the files? Isn't everything in there important?

It's not so much that zipped files have stuff taken out. It's more that the files have been reformatted to have the same information as before, but in a type of shorthand that computers can understand while still retaining all the same info as before.

And just like the dehydrated meat loaf, before you can dig in to a zipped file, you have to revert it to its former state. In the case of a zipped file, that means unzipping the file. This simply reformats the file back to its original state (and size). Unlike the meat loaf, though, this reconstituted file will be exactly as it was originally, not an imperfect match.

So how do you zip a file? Well, to zip a file (or compress it), you need to buy software like WinZip (http://www.winzip.com/) or StuffIt (http://www.stuffit.com/win/standard/).

And how do you unzip a file? To unzip a file (or expand it), there's FREE software like Stuffit Expander (http://www.aladdinsys.com/expander/index.html).

There's other ways and formats for compressing and expanding files, but the end result is the same -- smaller files.

And that's why Zip files are like dehydrated food.