Files, Filesystems, and Folders

A Windows Tutorial by Jon Baker

This is one of the most difficult concepts to grasp when being introduced to a PC for the first time. This whole business of “where” your letter or drawing is being “stored” and how to get at it.

I find that so many people when doing all this for the first time will by default go into the software they used to make the document to find it, say open Word to get at a letter as that's “where” they believe it is.

Hopefully this will explain how things actually work.

Your PC has in it many devices and components, one of them is called the hard disk or hard drive. This is also known by some people as a “Mass Storage Device” as that is what it is. This drive contains all the data on your computer, all of it, it's that simple. It contains Windows, all your other software such as Word and Windows Media Player and Internet Explorer plus all the files you've created. They are all stored on that hard drive.

Let me show you, open My Computer and be greated with something like this.

This listing (as under Windows XP with Show in Groups) shows that as well as a Floppy disk drive (A) and a CD drive (E) I have one hard disk, it's called System and it has the letter C (as is always true for a PC, the first hard drive is always given C).

This letter business, let me go through that. The computer needs some way to tell one drive from another, so it gives them all letters. The first floppy is always A, the second floppy always B, the first hard drive always C and then your other hard drives and CD/DVD drives just follow on from there. They are "addressed" like this if you have a file on your floppy disk called "Letter.doc" then the computer can get at it by opening "A:\Letter.doc". If you have a folder on your floppy called "My Stuff" and inside it you draw a picture called "Ugly.bmp" then it's located at "A:\My Stuff\Ugly.bmp". So you go to the right drive, then into whatever folder(s) you need to (if any) then get the file. That's how a computer's files are stored, in folders, in drives.

Now let's look into this hard drive, C.

Double click on your C drive, if you get a warning click the "Show files" link.

Here we see the contents of my hard drives "root", that is the folder C:\, the one before we go into any other folder. So the file "log" you see would be "C:\log.txt".

If you look in some folders on your hard drive you'll lots of files inside many folders, one of the ways to think about it is as follows. Consider a few filing cabinets, all together 3 of them, each with 3 drawers. This is the hard drive. Inside each of these drawers are cardboard wallets. These are your folders, inside of some folders. Inside these are some sheets of paper, your files.

Now Windows XP organises its files and folders. You see above we have a "Documents and Settings" folder, each users stuff is in there, "Program Files" is where your software will install itself to, and "Windows" (Yes, you guessed it!) is where Windows and all its junk is.

Now to one piece of terminology, you may see the word "Directory" used, that is what folders were called in the pre-Windows world.

So, why does all this matter you ask? Well, you know that "My Documents" folder you have that you shove loadsa junk into? Well, if you goto your file menu, then new, then folder you can create your own folders. If you goto file, rename, you can rename files and folders. By doing this and dragging some of your files around you can organise all your letters, pictures, music and everything else nice and neatly.

Now, all these files take up space, and your computer has a limited amount. When I say these files that includes all the software you installed, Windows and everything else on the hard drive, these are all files. Files are measured in Bytes. You get kilobytes, megabytes, gigabytes and terrabytes. A kilobytes is a 1024 bytes, a megabyte is 1024 kilobytes etc. Usually these days hard drives are measured in gigabytes, GB. To give you an idea of relative size here a one page letter takes up less than 100kB, a 4 minute song as an mp3 takes up around 4MB, a good quality photo takes up around 1MB. If you buy a computer now, most of them come with at least 40GB hard drives.

It's also worth remembering you can store files on floppies and CDs and DVDs (if you have writer drives). A floppy stores 1.44MB, a CD stores 700MB and a standard DVD stores 4.7GB. If you want to know the size of your hard drive (or hard drives if your lucky!) go into My Computer, right click on the hard drive you want to know about and click on "Properties". It will give you a pie chart showing free space, used space and total space.

One last thing, when I've been addressing things I've been using "File extsensions" like ".doc" and ".txt" and ".bmp". Windows hides these from you normally. Windows isn't magic, it doesn't magically know what's a Word document, what's a photo or what's an email. After the file name you see, they have a full stop and (usually) a three letter extension, this is the file extension. This is how Windows knows what icon to give it and what program to open it in when you double-click on it. ".doc" files are Word documents, ".jpg" are JPEG pictures, ".txt" are text files, ".mp3" are music files, ".htm" are web pages. There are literally hundreds of these.

Right, well, I think that covers the basics, I hope you understand how this filesystem business works a bit more now.

Thank you for reading.