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

JAVA file extension

Java Source Code File

Developer Files

PS file extension

PostScript File

Vector Image Files

HTML file extension

Hypertext Markup Language File

Web Files

TIFF file extension

Tagged Image File Format

Raster Image Files

AVI file extension

Audio Video Interleave File

Video Files

RAR file extension

WinRAR Compressed Archive

Compressed Files

SITX file extension

StuffIt X Archive

Compressed Files

TOAST file extension

Toast Disc Image

Disk Image Files

DMP file extension

Windows Memory Dump

System Files

7Z file extension

7-Zip Compressed File

Compressed Files

FON file extension

Generic Font File

Font Files

JS file extension

JavaScript File

Web Files

VCF file extension

vCard File

Data Files

MPG file extension

MPEG Video File

Video Files

GED file extension

GEDCOM Genealogy Data File

Data Files