Optimism is about accepting reality but looking forward to a better future, to a positive outcome. You accept that what you are going through right now is hard and tough but you now you can get through it and you are hopeful that something better is coming.
With optimism you accept the reality and train your mind to see pass that challenge to a brighter future.
For some people is easier to develop an optimistic mindset because you are accepting the reality, you are accepting all the negative, and wrong things going on, even all the sad things going on but you know that this won´t last forever and there are great things coming in the future. Optimism is that strong hope and belief that something better is coming.
Even when positivity and optimism have some differences, they still have at list one thing in common which is the way you choose to see every situation, the way you choose to see the world. We can´t deny that negativity is the worst you can do because the more you choose to see the world and every situation from a negative outlook the more negative situations will come to you and you keep living an unhealthy lifestyle full of unnecessary stress, fear and anxiety. When you choose to see every situation from a positive or optimistic outlook you are training your mind to stop looking for all the negative stuff going on and instead you work on looking for the positive things going on or the positive results or outcome, you can think about a better future after you overcome this challenge.