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

APK file extension

Android Package File

Executable Files

C file extension

C/C++ Source Code File

Developer Files

DBF file extension

Database File

Database Files

DEB file extension

Debian Software Package

Compressed Files

DTD file extension

Document Type Definition File

Developer Files

EXE file extension

Windows Executable File

Executable Files

MDB file extension

Microsoft Access Database

Database Files

PDB file extension

Program Database

Database Files

PPT file extension

PowerPoint Presentation

Data Files

PPTX file extension

PowerPoint Open XML Presentation

Data Files

SAV file extension

Saved Game

Game Files

SQL file extension

Structured Query Language Data File

Database Files

THM file extension

Thumbnail Image File

Raster Image Files

VCF file extension

vCard File

Data Files

WMV file extension

Windows Media Video File

Video Files