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

EPUB file extension

Open eBook File

eBook Files

7Z file extension

7-Zip Compressed File

Compressed Files

ASPX file extension

Active Server Page Extended File

Web Files

DMP file extension

Windows Memory Dump

System Files

M3U file extension

Media Playlist File

Audio Files

TGA file extension

Targa Graphic

Raster Image Files

PRF file extension

Outlook Profile File

Settings Files

DBF file extension

Database File

Database Files

LUA file extension

Lua Source File

Developer Files

HTM file extension

Hypertext Markup Language File

Web Files

MDF file extension

Media Disc Image File

Disk Image Files

JPG file extension

JPEG Image

Raster Image Files

XCODEPROJ file extension

Xcode Project

Developer Files

XLR file extension

Works Spreadsheet

Spreadsheet Files

MOV file extension

Apple QuickTime Movie

Video Files