Ask MAKE: Physical Computing Taxonomy

I hear a lot words -- embedded system, microcontroller, system on a chip, computer on a chip -- used somewhat interchangeably. What are the differences, if any? And where do Arduino and Raspberry Pi fit?

[original story: MAKE » Arduino]

MAKE » Arduino 18 Oct 20:00
arduino  ask make  computer on a chip  embedded system  microcontroller  raspberry pi  system on a chip