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

ASP file extension

Active Server Page

Web Files

DBF file extension

Database File

Database Files

JSP file extension

Java Server Page

Web Files

M4V file extension

iTunes Video File

Video Files

MID file extension

MIDI File

Audio Files

MOBI file extension

Mobipocket eBook

eBook Files

RM file extension

Real Media File

Video Files

SH file extension

Bash Shell Script

Developer Files

SITX file extension

StuffIt X Archive

Compressed Files

TAR file extension

Consolidated Unix File Archive

Data Files

VCXPROJ file extension

Visual C++ Project

Developer Files

VOB file extension

DVD Video Object File

Video Files

WMA file extension

Windows Media Audio File

Audio Files

XCODEPROJ file extension

Xcode Project

Developer Files

XLR file extension

Works Spreadsheet

Spreadsheet Files