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

CS file extension

Visual C# Source Code File

Developer Files

SRT file extension

SubRip Subtitle File

Video Files

DXF file extension

Drawing Exchange Format File

CAD Files

GZ file extension

Gnu Zipped Archive

Compressed Files

MPG file extension

MPEG Video File

Video Files

VOB file extension

DVD Video Object File

Video Files

EXE file extension

Windows Executable File

Executable Files

ROM file extension

N64 Game ROM File

Game Files

7Z file extension

7-Zip Compressed File

Compressed Files

CBR file extension

Comic Book RAR Archive

Compressed Files

M4A file extension

MPEG-4 Audio File

Audio Files

VCXPROJ file extension

Visual C++ Project

Developer Files

TMP file extension

Temporary File

Backup Files

ISO file extension

Disc Image File

Disk Image Files

ODT file extension

OpenDocument Text Document

Text Files