Followers: The first list is of people who follow you. It apparently does not have a limit. It can't be changed unless other users follow/unfollow you.
Following: The second list is of users you are following (you see their activity in your feed), which does have a limit. It can be reduced by unfollowing some users.
Follower = a person who follows you, who clicked 'follow' button on your profile, your follower. Following = a person whom you follow, you're his/her follower, you clicked 'follow' button on his/her profile.
Aad Hoogenboom, in my opinion, people who are in active most of time , need not to be followed, please reduce some of people who are not much engaged in this platform, be connected to people who are really working on this field, and unfollow rest