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

ASX file extension

Microsoft ASF Redirector File

Video Files

FLV file extension

Flash Video File

Video Files

GED file extension

GEDCOM Genealogy Data File

Data Files

GZ file extension

Gnu Zipped Archive

Compressed Files

HTML file extension

Hypertext Markup Language File

Web Files

JAR file extension

Java Archive File

Executable Files

MAX file extension

3ds Max Scene File

3D Image Files

MOV file extension

Apple QuickTime Movie

Video Files

PY file extension

Python Script

Developer Files

SAV file extension

Saved Game

Game Files

SWF file extension

Shockwave Flash Movie

Video Files

TIF file extension

Tagged Image File

Raster Image Files

TTF file extension

TrueType Font

Font Files

VOB file extension

DVD Video Object File

Video Files