Hello, Please excuse me if I may sound an ignorant compared to all of you, but I was always stupid and never paid attention to any of my physics classes and now I feel so stupid for missing on the most important subject of our lives and our universe. I was discussing a notion with a friend of mine 2 days ago, it's kind of a theory, I still don't know if it's new so I'm still writing an article about it. But I would like to know what is infinity? Does it have a fixed explanation or does it vary from one person to another? And is our universe infinite? I'd say no, if I'm wrong please correct me with a detailed explanation that I would be able to understand. Thanks!!