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

CBR file extension

Comic Book RAR Archive

Compressed Files

DEB file extension

Debian Software Package

Compressed Files

DXF file extension

Drawing Exchange Format File

CAD Files

GBR file extension

Gerber File

Data Files

MID file extension

MIDI File

Audio Files

PAGES file extension

Pages Document

Text Files

PKG file extension

Mac OS X Installer Package

Compressed Files

PNG file extension

Portable Network Graphic

Raster Image Files

RAR file extension

WinRAR Compressed Archive

Compressed Files

RM file extension

Real Media File

Video Files

SH file extension

Bash Shell Script

Developer Files

SQL file extension

Structured Query Language Data File

Database Files

TXT file extension

Plain Text File

Text Files

XLS file extension

Excel Spreadsheet

Spreadsheet Files