I have been reading and looking at videos regarding cosmic inflation and it said that the universe is flat. I am no expert and have no mathematical background - I love reading about space and learning new things about it. It just really irritates me when things go right over my head and this idea of a 'Flat Universe' is out my grasp, so please try and enlighten me. I would appreciate it if someone could explain it to me in a simple way or direct me to material that will give me an answer to a young laymen, like myself. What is it meant by a 'Flat Universe'? Thank you.