Why won’t my Minecraft world sync on different devices?

So I’ve always played Minecraft on PC (java edition), and recently downloaded PE on my phone so that I could play together with my brother. After a month or so, I downloaded it on my iPad as well and everything seemed fine. I had all of my worlds, and logged into the same account, but when I made a new world it didn’t appear on my phone? Also, if I ever edited one of my previous worlds, it didn’t appear on my phone either. Same thing happened when I built on my phone, the things I built wouldn’t appear from my iPad. I don’t know if this is normal or if I can fix it?? I’m very confused. I’ve done some research and can’t seem to find anyone asking the same question. Help!