I did some basic Arduino examples in the recent past, but I have never actually seen a shield for Arduino firsthand.
So I wonder: If I put a shield on an Arduino (for example, the Adafruit Motor Shield), does it "block" the entire Arduino, including all input and output pins?
Is it possible to use a shield, and still connect additional components that would usually connect directly to the Arduino (say, a potentiometer, or anything similar)? Does this depend on the type of Arduino, or on the type of the shield, or is it not possible at all?