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

ASF file extension

Advanced Systems Format File

Video Files

CER file extension

Internet Security Certificate

Web Files

CRX file extension

Chrome Extension

Plugin Files

VB file extension

VBScript File

Executable Files

WPS file extension

Microsoft Works Word Processor Document

Text Files

7Z file extension

7-Zip Compressed File

Compressed Files

PCT file extension

Picture File

Layout Files

BMP file extension

Bitmap Image File

Raster Image Files

TIFF file extension

Tagged Image File Format

Raster Image Files

EXE file extension

Windows Executable File

Executable Files

DRV file extension

Device Driver

System Files

DEB file extension

Debian Software Package

Compressed Files

AI file extension

Adobe Illustrator File

Vector Image Files

SYS file extension

Windows System File

System Files

PS file extension

PostScript File

Vector Image Files