This tutorial series teaches developers how to receive inbound voice calls using ASP.NET Core and the Vonage Voice API. It covers creating an ASP.NET app, setting up a NancyFX application, and handling inbound calls with NCCO responses. The tutorial requires a Vonage API account, Visual Studio 2017, and some configuration steps to link a Vonage phone number to the application. Once set up, developers can test their application by calling the linked Vonage number, which will return a dynamic response with the caller's phone number.