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

AIF file extension

Audio Interchange File Format

Audio Files

ASPX file extension

Active Server Page Extended File

Web Files

CER file extension

Internet Security Certificate

Web Files

CRDOWNLOAD file extension

Chrome Partially Downloaded File

Misc Files

DMP file extension

Windows Memory Dump

System Files

GPX file extension

GPS Exchange File

GIS Files

HTML file extension

Hypertext Markup Language File

Web Files

JPG file extension

JPEG Image

Raster Image Files

KMZ file extension

Google Earth Placemark File

GIS Files

LUA file extension

Lua Source File

Developer Files

M file extension

Objective-C Implementation File

Developer Files

RPM file extension

Red Hat Package Manager File

Compressed Files

TOAST file extension

Toast Disc Image

Disk Image Files

TXT file extension

Plain Text File

Text Files

ZIP file extension

Zipped File

Compressed Files