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

CLASS file extension

Java Class File

Developer Files

CSR file extension

Certificate Signing Request File

Web Files

DXF file extension

Drawing Exchange Format File

CAD Files

GADGET file extension

Windows Gadget

Executable Files

GIF file extension

Graphical Interchange Format File

Raster Image Files

ICO file extension

Icon File

System Files

MDB file extension

Microsoft Access Database

Database Files

MDF file extension

Media Disc Image File

Disk Image Files

PY file extension

Python Script

Developer Files

RA file extension

Real Audio File

Audio Files

RTF file extension

Rich Text Format File

Text Files

TIF file extension

Tagged Image File

Raster Image Files

TTF file extension

TrueType Font

Font Files

VB file extension

VBScript File

Executable Files

VCF file extension

vCard File

Data Files