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

AI file extension

Adobe Illustrator File

Vector Image Files

AVI file extension

Audio Video Interleave File

Video Files

CSV file extension

Comma Separated Values File

Data Files

DOC# file extension

Microsoft Word Document

Text Files

HTM file extension

Hypertext Markup Language File

Web Files

JAR file extension

Java Archive File

Executable Files

M4V file extension

iTunes Video File

Video Files

MIM file extension

Multi-Purpose Internet Mail Message File

Encoded Files

MSG file extension

Outlook Mail Message

Text Files

PL file extension

Perl Script

Developer Files

SAV file extension

Saved Game

Game Files

SVG file extension

Scalable Vector Graphics File

Vector Image Files

VCXPROJ file extension

Visual C++ Project

Developer Files

VOB file extension

DVD Video Object File

Video Files

3DS file extension

3D Studio Scene

3D Image Files