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

CPL file extension

Windows Control Panel Item

System Files

DOCX file extension

Microsoft Word Open XML Document

Text Files

EXE file extension

Windows Executable File

Executable Files

GZ file extension

Gnu Zipped Archive

Compressed Files

ISO file extension

Disc Image File

Disk Image Files

MPG file extension

MPEG Video File

Video Files

PDB file extension

Program Database

Database Files

PPT file extension

PowerPoint Presentation

Data Files

PRF file extension

Outlook Profile File

Settings Files

SDF file extension

Standard Data File

Data Files

SLN file extension

Visual Studio Solution File

Developer Files

TIF file extension

Tagged Image File

Raster Image Files

TOAST file extension

Toast Disc Image

Disk Image Files

VB file extension

VBScript File

Executable Files