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

BAK file extension

Backup File

Backup Files

BAT file extension

DOS Batch File

Executable Files

CFM file extension

ColdFusion Markup File

Web Files

CPP file extension

C++ Source Code File

Developer Files

CSV file extension

Comma Separated Values File

Data Files

EPUB file extension

Open eBook File

eBook Files

GPX file extension

GPS Exchange File

GIS Files

IBOOKS file extension

Multi-Touch iBook

Data Files

JSP file extension

Java Server Page

Web Files

M3U file extension

Media Playlist File

Audio Files

PDB file extension

Program Database

Database Files

PIF file extension

Program Information File

Executable Files

SRT file extension

SubRip Subtitle File

Video Files

WSF file extension

Windows Script File

Executable Files