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

DRV file extension

Device Driver

System Files

TIF file extension

Tagged Image File

Raster Image Files

DXF file extension

Drawing Exchange Format File

CAD Files

APK file extension

Android Package File

Executable Files

CUE file extension

Cue Sheet File

Disk Image Files

7Z file extension

7-Zip Compressed File

Compressed Files

MSG file extension

Outlook Mail Message

Text Files

CFM file extension

ColdFusion Markup File

Web Files

ASPX file extension

Active Server Page Extended File

Web Files

PART file extension

Partially Downloaded File

Misc Files

MOV file extension

Apple QuickTime Movie

Video Files

MP3 file extension

MP3 Audio File

Audio Files

DBF file extension

Database File

Database Files

PRF file extension

Outlook Profile File

Settings Files

LOG file extension

Log File

Text Files