The Interactive Glossary: Defining the Net
File Extension
When downloading content from the Web, you will undoubtedly encounter many different types of electronic file formats. The way to identify the file type is by looking at its extension, typically expressed as a dot followed by 2 to 4 letters (.xxx). Why should you care? You need to identify the file type to know whether it will work on your computer and whether you will need a particular type of software to decompress, play or view it.
Learn more: File Formats and Extensions
