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

CPL file extension

Windows Control Panel Item

System Files

CRX file extension

Chrome Extension

Plugin Files

DXF file extension

Drawing Exchange Format File

CAD Files

EPS file extension

Encapsulated PostScript File

Vector Image Files

FLA file extension

Adobe Flash Animation

Developer Files

FLV file extension

Flash Video File

Video Files

ISO file extension

Disc Image File

Disk Image Files

JSP file extension

Java Server Page

Web Files

MOV file extension

Apple QuickTime Movie

Video Files

PDF file extension

Portable Document Format File

Layout Files

RM file extension

Real Media File

Video Files

SDF file extension

Standard Data File

Data Files

TAX2012 file extension

TurboTax 2012 Tax Return

Data Files

TIFF file extension

Tagged Image File Format

Raster Image Files

XCODEPROJ file extension

Xcode Project

Developer Files