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

BAT file extension

DOS Batch File

Executable Files

CAB file extension

Windows Cabinet File

System Files

CER file extension

Internet Security Certificate

Web Files

DBF file extension

Database File

Database Files

DRV file extension

Device Driver

System Files

EPS file extension

Encapsulated PostScript File

Vector Image Files

EPUB file extension

Open eBook File

eBook Files

GBR file extension

Gerber File

Data Files

HTML file extension

Hypertext Markup Language File

Web Files

M file extension

Objective-C Implementation File

Developer Files

M3U file extension

Media Playlist File

Audio Files

MSG file extension

Outlook Mail Message

Text Files

PIF file extension

Program Information File

Executable Files

WAV file extension

WAVE Audio File

Audio Files

XML file extension

XML File

Data Files