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

CBR file extension

Comic Book RAR Archive

Compressed Files

CGI file extension

Common Gateway Interface Script

Executable Files

DBF file extension

Database File

Database Files

GZ file extension

Gnu Zipped Archive

Compressed Files

IFF file extension

Interchange File Format

Audio Files

MP3 file extension

MP3 Audio File

Audio Files

PAGES file extension

Pages Document

Text Files

PKG file extension

Mac OS X Installer Package

Compressed Files

PY file extension

Python Script

Developer Files

SQL file extension

Structured Query Language Data File

Database Files

SVG file extension

Scalable Vector Graphics File

Vector Image Files

SWF file extension

Shockwave Flash Movie

Video Files

SYS file extension

Windows System File

System Files

VCF file extension

vCard File

Data Files

WMA file extension

Windows Media Audio File

Audio Files