What is the difference between the iPad and the iPad 2?
The iPad 2 has a Gyroscope, is 8.8mm thick (compared to 13.4mm) and supports Verizon.
What is the difference between iPad I and iPad II?
The iPad 2 has front and back facing cameras, is thinner,
lighter, has a gyroscope (which tracks when you move around) and is
faster than the original iPad.