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

ASPX file extension

Active Server Page Extended File

Web Files

BIN file extension

Binary Disc Image

Disk Image Files

DESKTHEMEPACK file extension

Windows 8 Desktop Theme Pack File

System Files

H file extension

C/C++/Objective-C Header File

Developer Files

KMZ file extension

Google Earth Placemark File

GIS Files

LNK file extension

Windows File Shortcut

System Files

MAX file extension

3ds Max Scene File

3D Image Files

MID file extension

MIDI File

Audio Files

MIM file extension

Multi-Purpose Internet Mail Message File

Encoded Files

OBJ file extension

Wavefront 3D Object File

3D Image Files

PDB file extension

Program Database

Database Files

ROM file extension

N64 Game ROM File

Game Files

TMP file extension

Temporary File

Backup Files

WSF file extension

Windows Script File

Executable Files

ZIP file extension

Zipped File

Compressed Files