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

WAV file extension

WAVE Audio File

Audio Files

MDB file extension

Microsoft Access Database

Database Files

DEM file extension

Video Game Demo File

Game Files

XML file extension

XML File

Data Files

PAGES file extension

Pages Document

Text Files

VCXPROJ file extension

Visual C++ Project

Developer Files

CSR file extension

Certificate Signing Request File

Web Files

MP3 file extension

MP3 Audio File

Audio Files

TTF file extension

TrueType Font

Font Files

LUA file extension

Lua Source File

Developer Files

XLSX file extension

Microsoft Excel Open XML Spreadsheet

Spreadsheet Files

DDS file extension

DirectDraw Surface

Raster Image Files

JPG file extension

JPEG Image

Raster Image Files

TARGZ file extension

Compressed Tarball File

Compressed Files

7Z file extension

7-Zip Compressed File

Compressed Files