I need to arrange those concepts in my head:
Does Entity Framework is "the new" ADO .NET? What is the difference between those two terms? And how does LINQ to SQL related to each one?
Is it part of the entity framework?
Entity Framework is an O/R mapper which is built on top of ADO.NET. LINQ to SQL is another alternative O/R mapping approach, but as far as I know, Microsoft goes for Entity Framework in future rather than LINQ to SQL.