File extensions – definition and basic information


File extensions are the integral parts of the files that are on each computer. Often, when working on a computer, we encounter a wide range of files, such as docx, ppt, part, mp3 or rmvb. We realize that they are there – but we often do not know what they are for on our computer.

File extension, also known as the filename extension is a suffix added to the name of a computer file, usually consisting of a number of characters placed after the last dot in the filename, which gives us information about its coding. In other words a file extension is a file format. It allows the operating system (e.g. Windows) to recognize what program it should try to open the file.

In the table below you will find a random selection of popular file extensions.


File extension The full name of the file Category

BAT file extension

DOS Batch File

Executable Files

CBR file extension

Comic Book RAR Archive

Compressed Files

GADGET file extension

Windows Gadget

Executable Files

HTM file extension

Hypertext Markup Language File

Web Files

ICO file extension

Icon File

System Files

KEYCHAIN file extension

Mac OS X Keychain File

Data Files

MID file extension

MIDI File

Audio Files

MP3 file extension

MP3 Audio File

Audio Files

PL file extension

Perl Script

Developer Files

SQL file extension

Structured Query Language Data File

Database Files

TAR file extension

Consolidated Unix File Archive

Data Files

TEX file extension

LaTeX Source Document

Text Files

TMP file extension

Temporary File

Backup Files

WMA file extension

Windows Media Audio File

Audio Files

XLR file extension

Works Spreadsheet

Spreadsheet Files