I agree that the OP sounds very incorrect, but there is one thing that is notably different, and that would be web development. The classic ASP.NET and the mode

I agree that the OP sounds very incorrect, but there is one thing that is notably different, and that would be web development. The classic ASP.NET and the modern ASP.NET Core are not compatible with each other, and have different development styles in some areas. But other than that, most code out there should work with both.