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

7Z file extension

7-Zip Compressed File

Compressed Files

DOC# file extension

Microsoft Word Document

Text Files

PPT file extension

PowerPoint Presentation

Data Files

CSR file extension

Certificate Signing Request File

Web Files

BAK file extension

Backup File

Backup Files

RAR file extension

WinRAR Compressed Archive

Compressed Files

DRV file extension

Device Driver

System Files

KMZ file extension

Google Earth Placemark File

GIS Files

PPS file extension

PowerPoint Slide Show

Data Files

CRDOWNLOAD file extension

Chrome Partially Downloaded File

Misc Files

MSI file extension

Windows Installer Package

Misc Files

JAVA file extension

Java Source Code File

Developer Files

DBF file extension

Database File

Database Files

DXF file extension

Drawing Exchange Format File

CAD Files

SVG file extension

Scalable Vector Graphics File

Vector Image Files