The Followers and Following tabs from Chris M. 3's User Page.

In most social networks, the term "Follow" means to subscribe to a user and view new activity from that user. Miiverse is no exception. If you follow somebody in Miiverse, all of his recent posts will be featured in your Activity Feed. The same thing goes if somebody follows you. You can view your followers and users you're following in the Connections windows of your User Page.