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

DOC# file extension

Microsoft Word Document

Text Files

TIF file extension

Tagged Image File

Raster Image Files

AZW file extension

Amazon Kindle eBook File

eBook Files

MDB file extension

Microsoft Access Database

Database Files

VCD file extension

Virtual CD

Disk Image Files

ASF file extension

Advanced Systems Format File

Video Files

GED file extension

GEDCOM Genealogy Data File

Data Files

MSG file extension

Outlook Mail Message

Text Files

7Z file extension

7-Zip Compressed File

Compressed Files

ACCDB file extension

Access 2007 Database File

Database Files

SITX file extension

StuffIt X Archive

Compressed Files

M file extension

Objective-C Implementation File

Developer Files

MAX file extension

3ds Max Scene File

3D Image Files

SLN file extension

Visual Studio Solution File

Developer Files

AIF file extension

Audio Interchange File Format

Audio Files