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

ASF file extension

Advanced Systems Format File

Video Files

SQL file extension

Structured Query Language Data File

Database Files

PL file extension

Perl Script

Developer Files

MPG file extension

MPEG Video File

Video Files

CSR file extension

Certificate Signing Request File

Web Files

KML file extension

Keyhole Markup Language File

GIS Files

GBR file extension

Gerber File

Data Files

LNK file extension

Windows File Shortcut

System Files

7Z file extension

7-Zip Compressed File

Compressed Files

JAVA file extension

Java Source Code File

Developer Files

PHP file extension

PHP Source Code File

Web Files

WAV file extension

WAVE Audio File

Audio Files

DWG file extension

AutoCAD Drawing Database File

CAD Files

DOCX file extension

Microsoft Word Open XML Document

Text Files

PSPIMAGE file extension

PaintShop Pro Image

Raster Image Files