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

CSV file extension

Comma Separated Values File

Data Files

DNG file extension

Digital Negative Image File

Camera Raw Files

DOC file extension

Microsoft Word Document

Text Files

DOCX file extension

Microsoft Word Open XML Document

Text Files

EPS file extension

Encapsulated PostScript File

Vector Image Files

HQX file extension

BinHex 4.0 Encoded File

Encoded Files

ICS file extension

iCalendar File

Misc Files

MPG file extension

MPEG Video File

Video Files

ODT file extension

OpenDocument Text Document

Text Files

PDB file extension

Program Database

Database Files

PIF file extension

Program Information File

Executable Files

PS file extension

PostScript File

Vector Image Files

SWF file extension

Shockwave Flash Movie

Video Files

VCF file extension

vCard File

Data Files

YUV file extension

YUV Encoded Image File

Raster Image Files