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

LOG file extension

Log File

Text Files

UUE file extension

Uuencoded File

Encoded Files

PNG file extension

Portable Network Graphic

Raster Image Files

DOCX file extension

Microsoft Word Open XML Document

Text Files

RPM file extension

Red Hat Package Manager File

Compressed Files

PSPIMAGE file extension

PaintShop Pro Image

Raster Image Files

GPX file extension

GPS Exchange File

GIS Files

PL file extension

Perl Script

Developer Files

YUV file extension

YUV Encoded Image File

Raster Image Files

IFF file extension

Interchange File Format

Audio Files

SYS file extension

Windows System File

System Files

IBOOKS file extension

Multi-Touch iBook

Data Files

7Z file extension

7-Zip Compressed File

Compressed Files

DB file extension

Database File

Database Files

KMZ file extension

Google Earth Placemark File

GIS Files