Defining a type alias lets you explicitly choose which conflicting type you want to use in a given class, or create a more user-friendly name for a long-winded existing one. Type aliases are added at the top of the class file with a using directive, followed by the alias name and the assigned type:
using aliasName = type;
For instance, if we wanted to create a type alias to refer to the existing Int64 type, we could say the following:
using CustomInt = System.Int64;
Now that CustomInt is a type alias for the System.Int64 type, the compiler will treat it as an Int64, letting us use it like any other type:
public CustomInt playerHealth = 100;
You can use type aliasing with your custom types, or existing ones with the same syntax, as long as they're declared at the top of script files with the other using directives.