So, the point is that if you go under swimming pool, then outside you will not see clearly. And particularly if the water is moving, so someone is making the water turbulent, then you can even cannot even recognize someone you know or you cannot recognize a tree from a person etc. That is because you are you know you are observing through the water and the photons are getting sort of distorted. The same thing happens in air except it happens very minute at least so we don't really recognize that. When I am looking at you or you are looking at me, if the air in this room is turbulent you will see you will still recognize me. Hopefully, right? But for a telescope you are taking many many photons so your sensitivity is much more but with larger sensitivity also comes this problem that if there is turbulent air in the atmosphere or even if there is no turbulence as the you know just there is a thick atmosphere, then you do not observe perfectly. So, the angular resolution that I was mentioning that is also not you are not getting the diffraction limited angular resolution, your angular resolution is limited by this kind of effects. So, this is called atmospheric scene.