Following is a new feature in SharePoint 2013, where you can follow interest in specific document or person, site or tag etc. Once you follow an item then new activities about that particular item will appear in newsfeed of the users my site.
Also you can check my previous posts on:
We can configure Following through Central Administration. And also you need to be an administrator for the user profile service application.
Follow below steps:
Open SharePoint 2013 central administration, Then go to the Application Management section. Then from the Application Management page, Click on Manage service application under Service Applications.
Then select the user profile service application from the list of service applications. After that click on Manage from the Ribbon.
This will open the Manage Profile Service page for the particular App.
From there click on Manage Following link from the My Site Settings section.
This will open the Manage Following page, where you can do settings for Maximum number of followed people (Default and Maximum value is 1000), Maximum number of followed documents (Default and Maximum value is 500), Maximum number of followed sites (Default and Maximum value is 500) etc.