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

ASF file extension

Advanced Systems Format File

Video Files

BAT file extension

DOS Batch File

Executable Files

CFM file extension

ColdFusion Markup File

Web Files

CSV file extension

Comma Separated Values File

Data Files

FON file extension

Generic Font File

Font Files

INDD file extension

Adobe InDesign Document

Layout Files

MAX file extension

3ds Max Scene File

3D Image Files

ODT file extension

OpenDocument Text Document

Text Files

PDF file extension

Portable Document Format File

Layout Files

PPTX file extension

PowerPoint Open XML Presentation

Data Files

PY file extension

Python Script

Developer Files

RTF file extension

Rich Text Format File

Text Files

TEX file extension

LaTeX Source Document

Text Files

VB file extension

VBScript File

Executable Files