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

ACCDB file extension

Access 2007 Database File

Database Files

AVI file extension

Audio Video Interleave File

Video Files

CBR file extension

Comic Book RAR Archive

Compressed Files

CUE file extension

Cue Sheet File

Disk Image Files

DB file extension

Database File

Database Files

DNG file extension

Digital Negative Image File

Camera Raw Files

DRV file extension

Device Driver

System Files

M file extension

Objective-C Implementation File

Developer Files

MP3 file extension

MP3 Audio File

Audio Files

PPT file extension

PowerPoint Presentation

Data Files

RAR file extension

WinRAR Compressed Archive

Compressed Files

SDF file extension

Standard Data File

Data Files

TGA file extension

Targa Graphic

Raster Image Files

TIFF file extension

Tagged Image File Format

Raster Image Files

3DM file extension

Rhino 3D Model

3D Image Files