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

CSV file extension

Comma Separated Values File

Data Files

FLV file extension

Flash Video File

Video Files

LUA file extension

Lua Source File

Developer Files

MAX file extension

3ds Max Scene File

3D Image Files

MID file extension

MIDI File

Audio Files

MP3 file extension

MP3 Audio File

Audio Files

OTF file extension

OpenType Font

Font Files

RAR file extension

WinRAR Compressed Archive

Compressed Files

ROM file extension

N64 Game ROM File

Game Files

SRT file extension

SubRip Subtitle File

Video Files

TGA file extension

Targa Graphic

Raster Image Files

WAV file extension

WAVE Audio File

Audio Files

XCODEPROJ file extension

Xcode Project

Developer Files

XLS file extension

Excel Spreadsheet

Spreadsheet Files

3DM file extension

Rhino 3D Model

3D Image Files