CYBER NOTES October, 2004 by Dave Benore

The Importance of Files

In August we talked about the main pieces of computer hardware. In September we talked about what happens when a computer boots up. In both cases a computer’s hard drive was involved. This is one part of the computer’s memory. The other part is RAM (random access memory). RAM, you may remember, communicates directly with the CPU (the “brain”, the “chip”, the Pentium chip in a PC).

RAM gets its information from a hard disk, a floppy disk, a CD disk, a scanner, a digital camera, etc. Here we’re concerned with RAM getting information from either the hard disk, a floppy disk, or a CD disk. That information is stored on those disks as “files”. A computer file is a concept that simply must be understood.

When a person writes a letter on a computer and saves it, usually to the hard disk, he stores a “file”. He must give it a name so the computer can find it later. The file is the collection of alphabetic characters that make up the letter. It’s a collection of “data”, not instructions for the computer. Therefore it’s called a data file.

When a person takes a picture with a digital camera and “downloads” it to his computer, and saves it, he stores a file. Again, he must give it a name so the computer can find it later. (Some download programs may assign a temporary name, which can be changed.) This file is a collection of data that can be reconstructed into a photo. Again, it is a data file. It contains no instructions for the computer within it.

See the picture? A file is simply a collection or “group” of alphanumeric characters. (Alphanumeric, perhaps a new word to some, means any of the alphabetic characters, or numbers, or punctuation symbols.) These files, when they contain no instructions for the computer to follow, are called “data” files.

These data files can be stored under different categories. Microsoft calls these categories “folders”, to invoke the mental image of a manila file folder. Each folder can hold a very large number of files (hundreds at least, maybe thousands). Every folder, like every file, must have a name. (You can name your own folders.)

Just as you can “put” (save) more than one file into a folder, you can put one folder inside another, creating a “sub-folder” (although it’s still called just a folder). Thus you can “nest” folders inside other folders ad nauseum.

So—are data files the only kinds there are? Nope! But they are the kinds you create most of the time. There are three more main types of files; program files, configuration files, and driver files. All of these are created by computer programmers.

Program files contain instructions for the computer, telling it what to do with your data, how to talk to the hard disk, how to store information in RAM, etc.

Configuration files are special data files that tell your computer many things, like what background to show on your monitor screen (called “wallpaper” by Microsoft, for cripes sake), and what language to use—English, German, or what. The computer’s operating system (Windows for a PC) is a series of program files that use the configuration files very heavily. The operating system tells the CPU how to show data on the monitor, how to run the printer, how to “listen” to the keyboard and the mouse, etc.

Driver files are a kind of interpreter. Each peripheral device like a printer or scanner, “speaks” its own language (its own code). The driver files tell the computer how to “speak” to the printer, for example, so the printer prints correctly.

Regardless of what type of file a file may be, it will have a name and be stored in a folder somewhere. Its name and the folder or group of nested folders that contain it, provides the computer with a way to find any specific file out of many thousands. (My computer has well over 100,000 files on the hard drive. Yours may also.)

To see the file structure on your hard disk, use the program “Windows Explorer” (not Internet Explorer). Using Windows XP, from the start button go to “all programs”, then “accessories”, then “Windows Explorer”. Click Windows Explorer. The left pane shows the folder/subfolder structure (click on the little +signs to expand the structure). The right pane shows whatever is in the folder that is selected (highlighted) in the left pane.

A word of caution: Be very careful about not dragging files or folders around by holding down the left mouse button while moving the mouse. That moves files or folders to different places that you may not want.

Windows Explorer is an extremely useful tool once you understand how it works. Read a manual about it before trying to move or copy files. (It’s too detailed for this column.) It will be covered by any book on the operating system, such as books about Win98, WinME, or WinXP.

So files are extremely important. All information going into a computer from a disk storage device, like a hard drive, is in the form of a file, having a name, and “residing” in a folder or sub-folder on some disk drive or other storage device. Files are the bread and butter of computers. Without files to “chew on”, computers would not work. Happy computing!