If you use an interface like esteem for example that doesn’t have the communities interface, yes you literally need to type that, but if you use PeakD or Hive.blog, you just use the community post button.

You now have two pages on your profile, a blog page and an all posts page. When you post in a community it doesn’t automatically show up on your blog, but it shows up on your all posts page. If you also want a post to show up on your blog, you can resteem your own post and that adds it to your blog as well.

The reason for all this is say you’re an artist, and want to keep your blog all about art, but you also enjoy chatting about puppies in the puppies community, you don’t need to flood your blog with puppies posts, you can still keep it all art but still engage in all the other communities.