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

CRDOWNLOAD file extension

Chrome Partially Downloaded File

Misc Files

CSR file extension

Certificate Signing Request File

Web Files

CUR file extension

Windows Cursor

System Files

FLA file extension

Adobe Flash Animation

Developer Files

FLV file extension

Flash Video File

Video Files

H file extension

C/C++/Objective-C Header File

Developer Files

JS file extension

JavaScript File

Web Files

JSP file extension

Java Server Page

Web Files

M4V file extension

iTunes Video File

Video Files

PLUGIN file extension

Mac OS X Plug-in

Plugin Files

PNG file extension

Portable Network Graphic

Raster Image Files

PPS file extension

PowerPoint Slide Show

Data Files

PS file extension

PostScript File

Vector Image Files

VB file extension

VBScript File

Executable Files

XCODEPROJ file extension

Xcode Project

Developer Files