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

7Z file extension

7-Zip Compressed File

Compressed Files

CBR file extension

Comic Book RAR Archive

Compressed Files

AI file extension

Adobe Illustrator File

Vector Image Files

MP4 file extension

MPEG-4 Video File

Video Files

CPL file extension

Windows Control Panel Item

System Files

SQL file extension

Structured Query Language Data File

Database Files

MID file extension

MIDI File

Audio Files

TIF file extension

Tagged Image File

Raster Image Files

TORRENT file extension

BitTorrent File

Misc Files

TAX2012 file extension

TurboTax 2012 Tax Return

Data Files

ASX file extension

Microsoft ASF Redirector File

Video Files

PPT file extension

PowerPoint Presentation

Data Files

DEB file extension

Debian Software Package

Compressed Files

JAR file extension

Java Archive File

Executable Files

CSV file extension

Comma Separated Values File

Data Files