Int32 is the System.Int32 class, while int is an alias for System.Int32.
The same applies for String (uppercase S) which is System.String,
while string (lowercase S) is an alias for System.String.
So basically int is the same thing as Int32, and string is the same
thing as Int32. It’s down to user’s preference which one to use but most
prefer to use int and string as they are easier to type and more
familiar among C++ programmers.