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

ASPX file extension

Active Server Page Extended File

Web Files

C file extension

C/C++ Source Code File

Developer Files

CFM file extension

ColdFusion Markup File

Web Files

CSV file extension

Comma Separated Values File

Data Files

DAT file extension

Data File

Data Files

EPS file extension

Encapsulated PostScript File

Vector Image Files

GADGET file extension

Windows Gadget

Executable Files

M file extension

Objective-C Implementation File

Developer Files

MIM file extension

Multi-Purpose Internet Mail Message File

Encoded Files

PS file extension

PostScript File

Vector Image Files

SDF file extension

Standard Data File

Data Files

SQL file extension

Structured Query Language Data File

Database Files

TAR file extension

Consolidated Unix File Archive

Data Files

WMA file extension

Windows Media Audio File

Audio Files

WPS file extension

Microsoft Works Word Processor Document

Text Files