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

AI file extension

Adobe Illustrator File

Vector Image Files

AVI file extension

Audio Video Interleave File

Video Files

BIN file extension

Binary Disc Image

Disk Image Files

CPL file extension

Windows Control Panel Item

System Files

DB file extension

Database File

Database Files

H file extension

C/C++/Objective-C Header File

Developer Files

MSG file extension

Outlook Mail Message

Text Files

PCT file extension

Picture File

Layout Files

PDB file extension

Program Database

Database Files

PSPIMAGE file extension

PaintShop Pro Image

Raster Image Files

PY file extension

Python Script

Developer Files

RAR file extension

WinRAR Compressed Archive

Compressed Files

TEX file extension

LaTeX Source Document

Text Files

WPD file extension

WordPerfect Document

Text Files

XML file extension

XML File

Data Files