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

AI file extension

Adobe Illustrator File

Vector Image Files

BMP file extension

Bitmap Image File

Raster Image Files

CPP file extension

C++ Source Code File

Developer Files

IFF file extension

Interchange File Format

Audio Files

JS file extension

JavaScript File

Web Files

LUA file extension

Lua Source File

Developer Files

RM file extension

Real Media File

Video Files

RPM file extension

Red Hat Package Manager File

Compressed Files

RTF file extension

Rich Text Format File

Text Files

SYS file extension

Windows System File

System Files

TEX file extension

LaTeX Source Document

Text Files

TTF file extension

TrueType Font

Font Files

ZIPX file extension

Extended Zip File

Compressed Files

3DM file extension

Rhino 3D Model

3D Image Files

3GP file extension

3GPP Multimedia File

Video Files