Computers only understand information in the form of 1s and 0s. When you create a computer file, you are storing all of your information in the form of 1s and 0s in such a way that it can be converted back into something meaningful. This process is called "encoding."
Your file is encoded in a fashion appropriate to the kind of information that it represents. Microsoft Word documents are encoded differently from image files, both of which are different from video or sound files. The type of encoding is the file format.
File Names and Extensions
File names include information in them that tells the computer how to interpret the encoded data. That information is passed in the extension of the file name. The extension is attached to the file name with a dot (for example, .doc, .pdf, .jpg). The extension indicates the file format and what programs can open it. Below, you'll find a list of the most common file types.
Occasionally files are saved without the proper extension. This is more common on Macs as Mac files have other ways of encoding file format information. But it does cause trouble for PCs. If you receive a file you can't open because there is no extension, you may be able to fix the file by adding the extension. You will need to know what kind of file you have received. You can find this out by making an educated guess or asking the sender. Once you know what kind of a file you have:
- Click the name of the file twice to select.
- Add a dot and then the proper extension.
- Your computer will probably ask you to confirm the change; select OK.