Short answer: nothing. string is an alias to System.String. This also holds true for int and System.Int32.
If you want my personal preference I always use the lowercase version aka the alias. Why? Because I don't need to add the following reference: using System; in each file. I know, it's a little OCDish, but what can I say...
Published on Jan 24, 2020
Tags: ASP.NET MVC and Web API Tutorial | c# | string