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

GZ file extension

Gnu Zipped Archive

Compressed Files

CBR file extension

Comic Book RAR Archive

Compressed Files

CPP file extension

C++ Source Code File

Developer Files

TAX2012 file extension

TurboTax 2012 Tax Return

Data Files

UUE file extension

Uuencoded File

Encoded Files

COM file extension

DOS Command File

Executable Files

PNG file extension

Portable Network Graphic

Raster Image Files

PSPIMAGE file extension

PaintShop Pro Image

Raster Image Files

H file extension

C/C++/Objective-C Header File

Developer Files

VB file extension

VBScript File

Executable Files

DNG file extension

Digital Negative Image File

Camera Raw Files

7Z file extension

7-Zip Compressed File

Compressed Files

VOB file extension

DVD Video Object File

Video Files

CAB file extension

Windows Cabinet File

System Files

ICO file extension

Icon File

System Files