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

GADGET file extension

Windows Gadget

Executable Files

LNK file extension

Windows File Shortcut

System Files

LUA file extension

Lua Source File

Developer Files

TIFF file extension

Tagged Image File Format

Raster Image Files

DMP file extension

Windows Memory Dump

System Files

JSP file extension

Java Server Page

Web Files

7Z file extension

7-Zip Compressed File

Compressed Files

CSS file extension

Cascading Style Sheet

Web Files

FNT file extension

Windows Font File

Font Files

PSPIMAGE file extension

PaintShop Pro Image

Raster Image Files

H file extension

C/C++/Objective-C Header File

Developer Files

RTF file extension

Rich Text Format File

Text Files

HTML file extension

Hypertext Markup Language File

Web Files

M file extension

Objective-C Implementation File

Developer Files

BIN file extension

Binary Disc Image

Disk Image Files