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

RPM file extension

Red Hat Package Manager File

Compressed Files

VCF file extension

vCard File

Data Files

NES file extension

Nintendo (NES) ROM File

Game Files

XML file extension

XML File

Data Files

TAR file extension

Consolidated Unix File Archive

Data Files

3GP file extension

3GPP Multimedia File

Video Files

FON file extension

Generic Font File

Font Files

WPS file extension

Microsoft Works Word Processor Document

Text Files

PNG file extension

Portable Network Graphic

Raster Image Files

DNG file extension

Digital Negative Image File

Camera Raw Files

UUE file extension

Uuencoded File

Encoded Files

DAT file extension

Data File

Data Files

XLSX file extension

Microsoft Excel Open XML Spreadsheet

Spreadsheet Files

7Z file extension

7-Zip Compressed File

Compressed Files

KEYCHAIN file extension

Mac OS X Keychain File

Data Files