There are a few differences. There really isn't anything major, but for one, the Active 2 has a speaker where the Active does not. If you're looking to be able to use your watch to make and receive phone calls you're not going to be able to use the Active other than to have it call and then use your phone or use a bluetooth headset that is paired to the watch. Also the Active 2 has a touch bezel that the Active does not. The screen size is bigger on the Active 2 as it has a smaller bezel size so has less room for the screen. Bixby can also speak back to you because of the speaker. Watch faces are customizable on the Active 2 whereas they are not on the Active.....There is also a few more sensors on the Active 2.