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

AZW file extension

Amazon Kindle eBook File

eBook Files

BAK file extension

Backup File

Backup Files

BMP file extension

Bitmap Image File

Raster Image Files

DBF file extension

Database File

Database Files

EXE file extension

Windows Executable File

Executable Files

ICNS file extension

Mac OS X Icon Resource File

System Files

MAX file extension

3ds Max Scene File

3D Image Files

MDB file extension

Microsoft Access Database

Database Files

PART file extension

Partially Downloaded File

Misc Files

PKG file extension

Mac OS X Installer Package

Compressed Files

TGA file extension

Targa Graphic

Raster Image Files

TMP file extension

Temporary File

Backup Files

VB file extension

VBScript File

Executable Files

WMA file extension

Windows Media Audio File

Audio Files

3GP file extension

3GPP Multimedia File

Video Files