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

HTM file extension

Hypertext Markup Language File

Web Files

SH file extension

Bash Shell Script

Developer Files

PHP file extension

PHP Source Code File

Web Files

C file extension

C/C++ Source Code File

Developer Files

7Z file extension

7-Zip Compressed File

Compressed Files

VCF file extension

vCard File

Data Files

DTD file extension

Document Type Definition File

Developer Files

JS file extension

JavaScript File

Web Files

BAK file extension

Backup File

Backup Files

GAM file extension

Saved Game File

Game Files

VCD file extension

Virtual CD

Disk Image Files

TARGZ file extension

Compressed Tarball File

Compressed Files

VB file extension

VBScript File

Executable Files

CUE file extension

Cue Sheet File

Disk Image Files

FLA file extension

Adobe Flash Animation

Developer Files