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

CS file extension

Visual C# Source Code File

Developer Files

DEM file extension

Video Game Demo File

Game Files

EPUB file extension

Open eBook File

eBook Files

IFF file extension

Interchange File Format

Audio Files

RA file extension

Real Audio File

Audio Files

RM file extension

Real Media File

Video Files

SDF file extension

Standard Data File

Data Files

SRT file extension

SubRip Subtitle File

Video Files

TEX file extension

LaTeX Source Document

Text Files

TIFF file extension

Tagged Image File Format

Raster Image Files

TMP file extension

Temporary File

Backup Files

TOAST file extension

Toast Disc Image

Disk Image Files

VCF file extension

vCard File

Data Files

VOB file extension

DVD Video Object File

Video Files