When you follow other members on the forum, you have the ability to view their activity in your own profile. This can be done by clicking the Following tab provided on your profile page. This would allow you to stay up to date for when some of your favorite members have posted content on the forum, liked a post on the forum, changed their forum status, among other updates. The activity page will also tell you how many members you are following, and you can view the complete list of members that you are following by clicking the member count toward the top of the page.
You also have the ability to view the activity from those that other members of the forum are following as well. You can do this by visiting the profile page of a member, and then click the Following tab. Here you'll see the activity of all of the members that are being followed by the account, and you would also have the ability to view all of the accounts that are being followed by the member by clicking the number count toward the top of the page.