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

PART file extension

Partially Downloaded File

Misc Files

MSG file extension

Outlook Mail Message

Text Files

KEY file extension

Keynote Presentation

Data Files

JSP file extension

Java Server Page

Web Files

XML file extension

XML File

Data Files

GPX file extension

GPS Exchange File

GIS Files

GED file extension

GEDCOM Genealogy Data File

Data Files

M file extension

Objective-C Implementation File

Developer Files

CRDOWNLOAD file extension

Chrome Partially Downloaded File

Misc Files

COM file extension

DOS Command File

Executable Files

PSD file extension

Adobe Photoshop Document

Raster Image Files

7Z file extension

7-Zip Compressed File

Compressed Files

DWG file extension

AutoCAD Drawing Database File

CAD Files

PDB file extension

Program Database

Database Files