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

CFM file extension

ColdFusion Markup File

Web Files

DB file extension

Database File

Database Files

DNG file extension

Digital Negative Image File

Camera Raw Files

DOC file extension

Microsoft Word Document

Text Files

EPS file extension

Encapsulated PostScript File

Vector Image Files

FON file extension

Generic Font File

Font Files

HTML file extension

Hypertext Markup Language File

Web Files

IBOOKS file extension

Multi-Touch iBook

Data Files

JAR file extension

Java Archive File

Executable Files

MP4 file extension

MPEG-4 Video File

Video Files

PNG file extension

Portable Network Graphic

Raster Image Files

RSS file extension

Rich Site Summary

Web Files

RTF file extension

Rich Text Format File

Text Files

TGA file extension

Targa Graphic

Raster Image Files