Following now shows their public activities on your feed.
Friend gives you the ability to send unlimited messages, write on their wall, and view friends only writings, photos, and videos.
If you are following a friend then their friends only material will also appear on your freed. When you send someone a friend request, you automatically follow them unless they have following turned off. Then you will follow when they accept your friend request. Finally unfollowing a friend removes their activities from your feed.