Question: what is the difference between an iwatch 1 and 3?
Answer: The Apple Watch Series 3 includes a faster dual-core processor and improved Siri. Unlike the Series 1, Siri on the Series 3 talks back to users. The Series 3 also features a barometric altimeter and GPS, whereas the Series 1 doesn't. The latest model features a 16GB capacity, while the Series 1 has an 8GB capacity.