Declares a parameter to a method. Each parameter has a name attribute with becomes a variable that is declared in the method body and has the value that was passed in to the method.
Type: element id, must be unique in the window
A unique identifier so that you can identify the parameter with. You can use this as a parameter to getElementById and other DOM functions and to reference the element in style sheets.
The name of the parameter. This will be declared as a variable within the method body and given the value passed in as the corresponding method parameter.