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

GADGET file extension

Windows Gadget

Executable Files

JAR file extension

Java Archive File

Executable Files

TMP file extension

Temporary File

Backup Files

TIFF file extension

Tagged Image File Format

Raster Image Files

RA file extension

Real Audio File

Audio Files

CER file extension

Internet Security Certificate

Web Files

INDD file extension

Adobe InDesign Document

Layout Files

SVG file extension

Scalable Vector Graphics File

Vector Image Files

7Z file extension

7-Zip Compressed File

Compressed Files

PY file extension

Python Script

Developer Files

TGA file extension

Targa Graphic

Raster Image Files

PSD file extension

Adobe Photoshop Document

Raster Image Files

DOCX file extension

Microsoft Word Open XML Document

Text Files

KMZ file extension

Google Earth Placemark File

GIS Files

PPT file extension

PowerPoint Presentation

Data Files