Smart goal's are the achievable good goal like you want to plant then a high class gardener that pay's good is a smart goal so smart goal's are the goal you like but can do even if it doesn't pay the most, Stretch goal is a dream job that you have trained far and wide for that has been your profession that you want most that even if you can't get you want and are best at, So the difference is smart goal's are achievable and your good at so you could and should get that goal stretch goal's are the one you want most that you have trained for most but may or may not get.