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

CRX file extension

Chrome Extension

Plugin Files

DTD file extension

Document Type Definition File

Developer Files

GAM file extension

Saved Game File

Game Files

GPX file extension

GPS Exchange File

GIS Files

HTML file extension

Hypertext Markup Language File

Web Files

JAR file extension

Java Archive File

Executable Files

M4A file extension

MPEG-4 Audio File

Audio Files

MDB file extension

Microsoft Access Database

Database Files

PRF file extension

Outlook Profile File

Settings Files

PS file extension

PostScript File

Vector Image Files

RPM file extension

Red Hat Package Manager File

Compressed Files

RSS file extension

Rich Site Summary

Web Files

SDF file extension

Standard Data File

Data Files

SH file extension

Bash Shell Script

Developer Files

TORRENT file extension

BitTorrent File

Misc Files