How to Explain File Extensions

To the average computer user, file extensions can be a little mysterious. They appear to be a set of random letters attached to the end of their file names. Extensions are actually suffixes to file names that indicate the file format of the contents. File extensions can be more easily understood if you know which extensions are the most commonly used, and that software companies often design their programs to save files with an extension that is specific to the program.

Instructions

1. Know that "doc" file extensions most often indicate a file that was created using some sort of word processing software. Microsoft Word is the most popular word processing program, and it saves files using the "doc extension.

2. Understand that the extension "xls" indicates that the file is probably a spreadsheet. Again, Microsoft leads the pack in spreadsheet software, and these files have an "xls" extension.

3. Know the common file extensions for graphical files. Some of the most frequently seen file extensions in this category are "jpeg," "bmp," and "gif."

4. Identify music and video files by their file extensions. Music files often have an "mp3," "wma" or "wav" extension, while video files have "mp4," "mpeg," "wmv" or "mov" extensions.

5. Use a file extension index for help in identifying some less common extensions and the file types with which they are associated.

Tips & Warnings

• If your Windows system cannot open a file with a certain extension, you either may not have the appropriate program installed, or you may have registry errors.

References

• Common File Extensions

Resources

• Alphabetic File Extension List