Continuing to build your C# foundation, you have explored the predefined types provided by C# and learned about the rich set of operations you can perform on them. You then learned about value and reference types, including how you can treat a value type as a reference type and how to create a nullable type.
You have written a few more simple C# applications to explore how these concepts work. Although these applications might not be glamorous, they help to complete your foundation, enabling you to build applications that are more advanced. As your foundation in C# grows, the examples and exercises expect you to do more work.