Ruby has three ways to pass information from a method call to a method definition: positional arguments, keyword arguments, and block arguments. Each of these ways has: A syntax to declare an argument of that type in a method definition A syntax to declare an argument of that type in a method call A class that can can be used to convert arbitrary objects into and out of method calls A text marker that is associated with that kind of argument, *, **, or &. Originally I was going to Better Know...
