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

XML file extension

XML File

Data Files

H file extension

C/C++/Objective-C Header File

Developer Files

TAR file extension

Consolidated Unix File Archive

Data Files

RPM file extension

Red Hat Package Manager File

Compressed Files

RTF file extension

Rich Text Format File

Text Files

MAX file extension

3ds Max Scene File

3D Image Files

PPS file extension

PowerPoint Slide Show

Data Files

7Z file extension

7-Zip Compressed File

Compressed Files

FON file extension

Generic Font File

Font Files

PSD file extension

Adobe Photoshop Document

Raster Image Files

CUE file extension

Cue Sheet File

Disk Image Files

COM file extension

DOS Command File

Executable Files

JAR file extension

Java Archive File

Executable Files

INI file extension

Windows Initialization File

Settings Files

ZIP file extension

Zipped File

Compressed Files