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

CPL file extension

Windows Control Panel Item

System Files

DMP file extension

Windows Memory Dump

System Files

DNG file extension

Digital Negative Image File

Camera Raw Files

FNT file extension

Windows Font File

Font Files

HQX file extension

BinHex 4.0 Encoded File

Encoded Files

ICS file extension

iCalendar File

Misc Files

JAVA file extension

Java Source Code File

Developer Files

JSP file extension

Java Server Page

Web Files

M4A file extension

MPEG-4 Audio File

Audio Files

PNG file extension

Portable Network Graphic

Raster Image Files

PSPIMAGE file extension

PaintShop Pro Image

Raster Image Files

SAV file extension

Saved Game

Game Files

TMP file extension

Temporary File

Backup Files

TTF file extension

TrueType Font

Font Files

WMA file extension

Windows Media Audio File

Audio Files