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

DNG file extension

Digital Negative Image File

Camera Raw Files

MAX file extension

3ds Max Scene File

3D Image Files

DEB file extension

Debian Software Package

Compressed Files

MDB file extension

Microsoft Access Database

Database Files

IFF file extension

Interchange File Format

Audio Files

ROM file extension

N64 Game ROM File

Game Files

TXT file extension

Plain Text File

Text Files

VB file extension

VBScript File

Executable Files

7Z file extension

7-Zip Compressed File

Compressed Files

TAR file extension

Consolidated Unix File Archive

Data Files

PKG file extension

Mac OS X Installer Package

Compressed Files

FLV file extension

Flash Video File

Video Files

JPG file extension

JPEG Image

Raster Image Files

PSPIMAGE file extension

PaintShop Pro Image

Raster Image Files

TMP file extension

Temporary File

Backup Files