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

HQX file extension

BinHex 4.0 Encoded File

Encoded Files

PIF file extension

Program Information File

Executable Files

GAM file extension

Saved Game File

Game Files

BAK file extension

Backup File

Backup Files

CUE file extension

Cue Sheet File

Disk Image Files

MSI file extension

Windows Installer Package

Misc Files

APK file extension

Android Package File

Executable Files

CBR file extension

Comic Book RAR Archive

Compressed Files

SQL file extension

Structured Query Language Data File

Database Files

TEX file extension

LaTeX Source Document

Text Files

HTM file extension

Hypertext Markup Language File

Web Files

GIF file extension

Graphical Interchange Format File

Raster Image Files

7Z file extension

7-Zip Compressed File

Compressed Files

DWG file extension

AutoCAD Drawing Database File

CAD Files

PS file extension

PostScript File

Vector Image Files