Are you using discord? I could explain you much more and easier there, but in general.. Communities are like "channels".. You can join them and all other people in there can directly post into the community. Also by opening the community view you have kind of a filter "of community" interest.. For example if you create a "History community" people can join it and post history related posts in there. Opening the community window will show you all other history related post directly.. There are communities for all kind of interests, fungi, food, gardening, gaming, etc.. There is no history community out there yet and I would definitely join.. This post here for example is posted into the "philosophy community" as i think it may be of interest to everyone who joined this "channel".. You can join as many communities as you wish to and watch into everyone seperately or at the same time for the content you are interested in 😁.. A bit hard to get the idea in the beginning but you get used to it very quickly ^^ I actually are hosting the "Amazing Nature Community" and are following the cat and photography communities, but also the philosophy and scientific ones too 😊