How to Group fields, and duplicate them?
You can also go for the Multifield module. More details from its project page:


  This project seeks to provide a true compound field solution for Drupal 7. As much as I love Field collection, it still has to save actual entities, and can cause performance problems due to having to load all the referenced field collection entities on node, or parent entity load.


How to use multifield check listed links :


Video demo Demo
How Creating multiple value field groups .