• A property invoked as an LValue is used as an assignment target.

• A property invoked as an RValue returns its value, which for a function or method is the function declaration.

• A property invoked as an RValue with the parentheses and some optional arguments is called as a function or method.

The distinction between a function and method is whether the script source text in the function body makes use of the 'this' keyword to operate on the receiving objects properties.