What is a microcontroller?
A microcontroller is at its heart a programmable microchip that can be used to control sensors (heat, light, sound, etc.), motors and other electronic devices. It can be used as a stand-alone device or in connection with a computer. It is the heart of many small robots, remote control cars and almost all electronic devices (including most likely your toaster.)
When would someone use a microcontoller?
If you are thinking of making art that any sort smart element to it: recognizing a viewers presence, controlling motion of an object, having a small electronic device communicate with a computer or the internet, then a microcontroller might be what your looking for.
Where do I start?
There are many possible options of microcontrollers. Today many of these options are cheap, interface with cheap or free software, are easy to learn and there are large online communities to work with.
This section of the database will go over some of your options.