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

ACCDB file extension

Access 2007 Database File

Database Files

CGI file extension

Common Gateway Interface Script

Executable Files

CRDOWNLOAD file extension

Chrome Partially Downloaded File

Misc Files

DMG file extension

Mac OS X Disk Image

Disk Image Files

DNG file extension

Digital Negative Image File

Camera Raw Files

M file extension

Objective-C Implementation File

Developer Files

PAGES file extension

Pages Document

Text Files

PLUGIN file extension

Mac OS X Plug-in

Plugin Files

PS file extension

PostScript File

Vector Image Files

SH file extension

Bash Shell Script

Developer Files

SQL file extension

Structured Query Language Data File

Database Files

TAR file extension

Consolidated Unix File Archive

Data Files

TAX2012 file extension

TurboTax 2012 Tax Return

Data Files

VCF file extension

vCard File

Data Files

VCXPROJ file extension

Visual C++ Project

Developer Files