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

JSP file extension

Java Server Page

Web Files

PY file extension

Python Script

Developer Files

7Z file extension

7-Zip Compressed File

Compressed Files

JS file extension

JavaScript File

Web Files

EPS file extension

Encapsulated PostScript File

Vector Image Files

3GP file extension

3GPP Multimedia File

Video Files

TORRENT file extension

BitTorrent File

Misc Files

FNT file extension

Windows Font File

Font Files

CSS file extension

Cascading Style Sheet

Web Files

MOV file extension

Apple QuickTime Movie

Video Files

UUE file extension

Uuencoded File

Encoded Files

PPS file extension

PowerPoint Slide Show

Data Files

MPG file extension

MPEG Video File

Video Files

NES file extension

Nintendo (NES) ROM File

Game Files

TXT file extension

Plain Text File

Text Files