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

JAVA file extension

Java Source Code File

Developer Files

KMZ file extension

Google Earth Placemark File

GIS Files

IBOOKS file extension

Multi-Touch iBook

Data Files

PDF file extension

Portable Document Format File

Layout Files

DBF file extension

Database File

Database Files

SVG file extension

Scalable Vector Graphics File

Vector Image Files

GZ file extension

Gnu Zipped Archive

Compressed Files

3GP file extension

3GPP Multimedia File

Video Files

CBR file extension

Comic Book RAR Archive

Compressed Files

RA file extension

Real Audio File

Audio Files

7Z file extension

7-Zip Compressed File

Compressed Files

TORRENT file extension

BitTorrent File

Misc Files

INDD file extension

Adobe InDesign Document

Layout Files

IFF file extension

Interchange File Format

Audio Files

BIN file extension

Binary Disc Image

Disk Image Files