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

C file extension

C/C++ Source Code File

Developer Files

CRDOWNLOAD file extension

Chrome Partially Downloaded File

Misc Files

FON file extension

Generic Font File

Font Files

GIF file extension

Graphical Interchange Format File

Raster Image Files

MP4 file extension

MPEG-4 Video File

Video Files

PART file extension

Partially Downloaded File

Misc Files

PDB file extension

Program Database

Database Files

PDF file extension

Portable Document Format File

Layout Files

PNG file extension

Portable Network Graphic

Raster Image Files

PSD file extension

Adobe Photoshop Document

Raster Image Files

SVG file extension

Scalable Vector Graphics File

Vector Image Files

WPS file extension

Microsoft Works Word Processor Document

Text Files

XLR file extension

Works Spreadsheet

Spreadsheet Files

3G2 file extension

3GPP2 Multimedia File

Video Files