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

CBR file extension

Comic Book RAR Archive

Compressed Files

WMV file extension

Windows Media Video File

Video Files

CS file extension

Visual C# Source Code File

Developer Files

PSPIMAGE file extension

PaintShop Pro Image

Raster Image Files

PIF file extension

Program Information File

Executable Files

RTF file extension

Rich Text Format File

Text Files

AIF file extension

Audio Interchange File Format

Audio Files

7Z file extension

7-Zip Compressed File

Compressed Files

LNK file extension

Windows File Shortcut

System Files

CRX file extension

Chrome Extension

Plugin Files

SRT file extension

SubRip Subtitle File

Video Files

PY file extension

Python Script

Developer Files

SQL file extension

Structured Query Language Data File

Database Files

JAR file extension

Java Archive File

Executable Files

XCODEPROJ file extension

Xcode Project

Developer Files