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

CAB file extension

Windows Cabinet File

System Files

CFM file extension

ColdFusion Markup File

Web Files

CUR file extension

Windows Cursor

System Files

IFF file extension

Interchange File Format

Audio Files

M file extension

Objective-C Implementation File

Developer Files

MDF file extension

Media Disc Image File

Disk Image Files

PDB file extension

Program Database

Database Files

PS file extension

PostScript File

Vector Image Files

RAR file extension

WinRAR Compressed Archive

Compressed Files

TEX file extension

LaTeX Source Document

Text Files

TIF file extension

Tagged Image File

Raster Image Files

TOAST file extension

Toast Disc Image

Disk Image Files

WPD file extension

WordPerfect Document

Text Files

WSF file extension

Windows Script File

Executable Files

XLR file extension

Works Spreadsheet

Spreadsheet Files