Intro file extension
A file extensions is the last part (usually the three letters after the dot) of a file name, and is used to know what that file is, and so how to use it.
For example, the file travel.jpg has the extension JPG, and many users can imagine that it is an image file. Most important, your computer knows what a JPG file is too, and if double-clicked, it will try to open that file with the right application.
This works for other image files (GIF, PNG), audio files (MP3, WAV), documents (TXT, DOC).


Obviously a file can be renamed with a different file extension, and this could make that fire unreadable. A better way to know the real file type is usually reading the fists bytes of the file content. This is not true for all the file types, but is for most of them. (I'm working in a small application useful to detect the real file-type. Will be added in these pages shortly.)
If you think that you should be aware of any file type, consider that for each new application you install, a number of new known file extension will be added to your computer (i.e. MS Excel does not only adds XLS!)

What happens with all the applications you don't install? And what if you receive a file that you don't know how to open it?

This is why this site is here, to give a quick advice about unknown file types.
Click the first letter if the extension you are looking for, and browse until you find it.
BACK;