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

ASF file extension

Advanced Systems Format File

Video Files

CFG file extension

Configuration File

Settings Files

CPP file extension

C++ Source Code File

Developer Files

CUR file extension

Windows Cursor

System Files

DBF file extension

Database File

Database Files

GBR file extension

Gerber File

Data Files

GPX file extension

GPS Exchange File

GIS Files

GZ file extension

Gnu Zipped Archive

Compressed Files

HQX file extension

BinHex 4.0 Encoded File

Encoded Files

KML file extension

Keyhole Markup Language File

GIS Files

RAR file extension

WinRAR Compressed Archive

Compressed Files

SWF file extension

Shockwave Flash Movie

Video Files

TAX2012 file extension

TurboTax 2012 Tax Return

Data Files

VCXPROJ file extension

Visual C++ Project

Developer Files

XLR file extension

Works Spreadsheet

Spreadsheet Files