what is the difference between series 1 and series 4 apple watch?
Apple launched the first Apple Watch with support for two wireless standards: 2.4GHz 802.11b/g/n Wi-Fi, and Bluetooth 4.0. Wi-Fi has remained the same from generation to generation, but the Bluetooth was bumped to version 4.2 in the second year, and Series 4 takes a further step forward to Bluetooth 5.0.