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

APK file extension

Android Package File

Executable Files

BAT file extension

DOS Batch File

Executable Files

DRV file extension

Device Driver

System Files

HQX file extension

BinHex 4.0 Encoded File

Encoded Files

ICS file extension

iCalendar File

Misc Files

INI file extension

Windows Initialization File

Settings Files

JAVA file extension

Java Source Code File

Developer Files

MDF file extension

Media Disc Image File

Disk Image Files

PLUGIN file extension

Mac OS X Plug-in

Plugin Files

PPTX file extension

PowerPoint Open XML Presentation

Data Files

RM file extension

Real Media File

Video Files

SH file extension

Bash Shell Script

Developer Files

TAR file extension

Consolidated Unix File Archive

Data Files

VB file extension

VBScript File

Executable Files

XHTML file extension

Extensible Hypertext Markup Language File

Web Files