How can design Angular 2 in a intranet communication with sql server

I am trying to create an architecture for a web app. We are planning to develop the front-end using angular 2 + bootstrap and the DB will be SQL server. As per the requirement, this web app is accessible to an internal team only that means we have to keep it inside an intranet. So my doubt is how can we design the communication between WEB app to Database. What component should I use for this? Please suggest?