global class is something like public class in java. its acessible everywhere. All classes that contain methods defined with the webService keyword must be declared as global. If a method or inner class is declared as global, the outer, top-level class must also be defined as global.
private | public | global [virtual | abstract | with sharing | without sharing | (none)] class ClassName [implements InterfaceNameList | (none)] [extends ClassName | (none)] { // The body of the class
global class is something like public class in java. its acessible everywhere. All classes that contain methods defined with the webService keyword must be declared as global. If a method or inner class is declared as global, the outer, top-level class must also be defined as global.