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

PY file extension

Python Script

Developer Files

CPL file extension

Windows Control Panel Item

System Files

KMZ file extension

Google Earth Placemark File

GIS Files

C file extension

C/C++ Source Code File

Developer Files

7Z file extension

7-Zip Compressed File

Compressed Files

TARGZ file extension

Compressed Tarball File

Compressed Files

LOG file extension

Log File

Text Files

PPT file extension

PowerPoint Presentation

Data Files

3DS file extension

3D Studio Scene

3D Image Files

RPM file extension

Red Hat Package Manager File

Compressed Files

DNG file extension

Digital Negative Image File

Camera Raw Files

AVI file extension

Audio Video Interleave File

Video Files

PHP file extension

PHP Source Code File

Web Files

DESKTHEMEPACK file extension

Windows 8 Desktop Theme Pack File

System Files

DRV file extension

Device Driver

System Files