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

WSF file extension

Windows Script File

Executable Files

TIF file extension

Tagged Image File

Raster Image Files

TOAST file extension

Toast Disc Image

Disk Image Files

ICS file extension

iCalendar File

Misc Files

PRF file extension

Outlook Profile File

Settings Files

DXF file extension

Drawing Exchange Format File

CAD Files

FLV file extension

Flash Video File

Video Files

JAR file extension

Java Archive File

Executable Files

AZW file extension

Amazon Kindle eBook File

eBook Files

TGA file extension

Targa Graphic

Raster Image Files

DNG file extension

Digital Negative Image File

Camera Raw Files

7Z file extension

7-Zip Compressed File

Compressed Files

EXE file extension

Windows Executable File

Executable Files

RTF file extension

Rich Text Format File

Text Files

MSG file extension

Outlook Mail Message

Text Files