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

7Z file extension

7-Zip Compressed File

Compressed Files

ZIP file extension

Zipped File

Compressed Files

TEX file extension

LaTeX Source Document

Text Files

PAGES file extension

Pages Document

Text Files

HTM file extension

Hypertext Markup Language File

Web Files

BMP file extension

Bitmap Image File

Raster Image Files

XLR file extension

Works Spreadsheet

Spreadsheet Files

DNG file extension

Digital Negative Image File

Camera Raw Files

SITX file extension

StuffIt X Archive

Compressed Files

MID file extension

MIDI File

Audio Files

CRDOWNLOAD file extension

Chrome Partially Downloaded File

Misc Files

VOB file extension

DVD Video Object File

Video Files

DEB file extension

Debian Software Package

Compressed Files

FLA file extension

Adobe Flash Animation

Developer Files

CER file extension

Internet Security Certificate

Web Files