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

DEM file extension

Video Game Demo File

Game Files

FNT file extension

Windows Font File

Font Files

XLSX file extension

Microsoft Excel Open XML Spreadsheet

Spreadsheet Files

7Z file extension

7-Zip Compressed File

Compressed Files

MSG file extension

Outlook Mail Message

Text Files

RA file extension

Real Audio File

Audio Files

TGA file extension

Targa Graphic

Raster Image Files

CS file extension

Visual C# Source Code File

Developer Files

PL file extension

Perl Script

Developer Files

MP3 file extension

MP3 Audio File

Audio Files

3GP file extension

3GPP Multimedia File

Video Files

BMP file extension

Bitmap Image File

Raster Image Files

TXT file extension

Plain Text File

Text Files

DMP file extension

Windows Memory Dump

System Files

C file extension

C/C++ Source Code File

Developer Files