MCI makes it very simple to write a program which can play a wide variety of media files and even to record sound by just passing commands as strings.
It uses relations described in Windows registries or in the [MCI] section of the file system.ini.
One advantage of this API is that MCI commands can be transmitted both from the programming language and from the scripting language (open script, lingo aso).
After a few years[update], the MCI interface has been phased out in favor of the DirectX APIs first released in 1995.
To play a type of media, it needs to be initialized correctly using MCI commands.