All the information that's "in your computer" is actually stored on your computer's hard disk (often referred to as drive C:). In a sense, your hard disk is like a filing cabinet. And like a filing cabinet, the information on your hard disk is organized into files and folders. Figure 1 shows the simple analogy.
Just as a folder in a filing cabinet is a "container" for storing paper documents, a computer folder is a container for storing computer documents. A computer document, in turn, is anything that you might want to look at on the screen, or print on paper. That includes typed text, spreadsheets, and pictures. In the computer world, music (songs) and video (movies) are also documents. And just like any documents, music and video files are stored in folders.
You wouldn't want to open up your real filing cabinet and dump all its contents onto your real desk. You'd end up with a big disorganized mess. Your computer's hard disk can hold tens of thousands of files and folders. You wouldn't want all that stuff open on your Windows desktop (screen) at the same time, for the same reason. It would just be too much clutter.
A folder or file that's currently visible on your screen is said to be open. One that's still "in the filing cabinet", so to speak, is said to be closed. On your computer screen, all folders and files are represented by icons -- those little emblems you see all over the place. It's pretty easy to tell a folder from a file just from the icon. As a rule, icons that represent folders have a manila file folder as part of their icon, as in the top of Figure 2. Icons that represent documents usually have a little dog-eared sheet of paper as part of their icon, as in the bottom of Figure 2.
To open a folder or file, you typically double-click its icon. When you open a document, some program that's capable of displaying (or "playing") that document opens, and displays the document. For example, when you open a song (music) or a movie (video), Windows Media Player or some other program will open to play the document.
When you open a folder, a program named Windows Explorer opens and shows you the contents of that folder. I'll talk more about Windows Explorer in the next mini-tutorial, for those of you who are interested. For now, the main thing to focus on is understanding the different between folders and files. To recap:
A folder is a "container" in which you can store documents, like a manila file folder in a filing cabinet.
The icon for a folder will usually resemble a manila file folder in some way.
A file (or document) is like a paper document, something you store inside a manila file folder (though on a computer is can be a picture, song, or video as well as typed text).
Icons that represent documents usually have a dog-eared piece of paper as part of their icon.
A program is neither a document, nor a folder. A program is actually a "tool" that you use to create, view, or print documents. Icons for programs don't have either the manila file folder symbol, nor the dog-eared piece of paper. Rather, the icon for a program is just the program's logo. You can see this for yourself by clicking the Start button. As you can see down the left side of the sample Start menu in Figure 3, there are no manila folders or dog-eared sheets of paper in the programs' icons.
No document can open "by itself". A document must open within some program. When you double-click a document's icon, the document opens in the default program for that document type. The logo atop the "dog-eared sheet of paper" portion of a document's icon matches the logo of the default program for that document type. Figure 4 shows an example.
But the main points to remember from this mini-tutorial is that folders are "containers" for storing documents. The icon for a folder will always look like a manila folder, as in the examples shown in Figure 5.
Documents, on the other hand, are things like typed text, and pictures -- the types of things you might actually store in a filing cabinet if they were on paper rather than on a computer. To keep the "paper" analogy, icons that represent documents tend to sport a sheet of paper as part of their icon, as in the examples shown in Figure 6.