( This answer is regularly updated whenever a new .NET announcement is made, and it has been updated with details of ASP.NET Core 3.0, .NET 3, and .NET 5 ) Microsoft needs a good slapping for the amount of confusion over the past 3 years 5 years over .NET Core / DNX, ASP.NET Core, .NET Standard, .NET 5 and the rest. (and I'm saying that as a former FTE SE in DevDiv... ("hi from building 16!") ) ASP.NET aka "System.Web" is now dead. WebForms is dead (hurrah!) ASP.NET MVC launched in 2008 was built on-top of ASP.NET, but bypassed most of the WebForms infrastructure. ASP.NET MVC has its own versioning separate from ASP.NET and ASP.NET Web API (and ASP.NET Core ). You linked to ASP.NET MVC 5 's documentation - this is not the same thing as ASP.NET 5 . ASP.NET Web API launched in 2012 is a sibling of ASP.NET MVC , in that it built on-top of ASP.NET too, but had its own class library ( System.Web.Http ) that didn't share much with A...
Gives you back end support so you save time!