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

ACCDB file extension

Access 2007 Database File

Database Files

ASX file extension

Microsoft ASF Redirector File

Video Files

BIN file extension

Binary Disc Image

Disk Image Files

COM file extension

DOS Command File

Executable Files

DOC# file extension

Microsoft Word Document

Text Files

INI file extension

Windows Initialization File

Settings Files

MID file extension

MIDI File

Audio Files

MIM file extension

Multi-Purpose Internet Mail Message File

Encoded Files

PL file extension

Perl Script

Developer Files

RTF file extension

Rich Text Format File

Text Files

SITX file extension

StuffIt X Archive

Compressed Files

VB file extension

VBScript File

Executable Files

VCD file extension

Virtual CD

Disk Image Files

WAV file extension

WAVE Audio File

Audio Files

WMA file extension

Windows Media Audio File

Audio Files