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

ASF file extension

Advanced Systems Format File

Video Files

DMG file extension

Mac OS X Disk Image

Disk Image Files

EPS file extension

Encapsulated PostScript File

Vector Image Files

H file extension

C/C++/Objective-C Header File

Developer Files

JAVA file extension

Java Source Code File

Developer Files

MIM file extension

Multi-Purpose Internet Mail Message File

Encoded Files

MPG file extension

MPEG Video File

Video Files

PL file extension

Perl Script

Developer Files

TAX2012 file extension

TurboTax 2012 Tax Return

Data Files

TIFF file extension

Tagged Image File Format

Raster Image Files

WAV file extension

WAVE Audio File

Audio Files

XCODEPROJ file extension

Xcode Project

Developer Files

XLS file extension

Excel Spreadsheet

Spreadsheet Files

ZIP file extension

Zipped File

Compressed Files

3DS file extension

3D Studio Scene

3D Image Files