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

ASP file extension

Active Server Page

Web Files

BAK file extension

Backup File

Backup Files

CBR file extension

Comic Book RAR Archive

Compressed Files

COM file extension

DOS Command File

Executable Files

FLA file extension

Adobe Flash Animation

Developer Files

HTM file extension

Hypertext Markup Language File

Web Files

JSP file extension

Java Server Page

Web Files

M4V file extension

iTunes Video File

Video Files

MOV file extension

Apple QuickTime Movie

Video Files

OBJ file extension

Wavefront 3D Object File

3D Image Files

PY file extension

Python Script

Developer Files

TARGZ file extension

Compressed Tarball File

Compressed Files

TIFF file extension

Tagged Image File Format

Raster Image Files

TMP file extension

Temporary File

Backup Files

VCF file extension

vCard File

Data Files