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

ASPX file extension

Active Server Page Extended File

Web Files

BIN file extension

Binary Disc Image

Disk Image Files

DBF file extension

Database File

Database Files

GED file extension

GEDCOM Genealogy Data File

Data Files

H file extension

C/C++/Objective-C Header File

Developer Files

JSP file extension

Java Server Page

Web Files

LUA file extension

Lua Source File

Developer Files

PAGES file extension

Pages Document

Text Files

SAV file extension

Saved Game

Game Files

SITX file extension

StuffIt X Archive

Compressed Files

SRT file extension

SubRip Subtitle File

Video Files

SWF file extension

Shockwave Flash Movie

Video Files

TGA file extension

Targa Graphic

Raster Image Files

WPD file extension

WordPerfect Document

Text Files