When creating a new post, post author has the option to choose who will be notified about this post when it is published. If All Users is selected, then all blog users will receive email and push notification about the new post, as well as all invited users, even if they have not yet joined the blog.
If you use teams to organize your users, you can choose to notify only particular teams, instead of all users. This way post author can choose to notify only teams and users who are relevant to the post.
On the other hand, each user can follow a category or another user on the blog to make sure he/she is notified when there is something new posted in that category or by that user, even if post author did not explicitly select their team to be notified. This way users can proactively express their interest in the particular topic category and make sure they never miss a new post in that category (or a post by published by the particular user).
New Comment notifications
When someone comments on a post, all users who follow that post will be notified about the comment. By default, post author automatically follows all his/hers posts, which means that you will always be notified when someone comments on your post.
All users who comment on a post are automatically added as followers of that post, which means that they also will receive notifications for any new comments created from now on.
You can unfollow a post at any time to stop receiving comment notifications for that post.
One way to make sure someone is notified about your comment or post is to mention that user in your comment or a post. Mentioned user will receive an in-app and email notification about your comment or post.