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

AZW file extension

Amazon Kindle eBook File

eBook Files

PDF file extension

Portable Document Format File

Layout Files

XCODEPROJ file extension

Xcode Project

Developer Files

DRV file extension

Device Driver

System Files

GPX file extension

GPS Exchange File

GIS Files

MSI file extension

Windows Installer Package

Misc Files

CLASS file extension

Java Class File

Developer Files

VCXPROJ file extension

Visual C++ Project

Developer Files

WSF file extension

Windows Script File

Executable Files

DNG file extension

Digital Negative Image File

Camera Raw Files

TIF file extension

Tagged Image File

Raster Image Files

JPG file extension

JPEG Image

Raster Image Files

CER file extension

Internet Security Certificate

Web Files

7Z file extension

7-Zip Compressed File

Compressed Files

DBF file extension

Database File

Database Files