Guid.NewGuid() is calling the static NewGuid() method on the Guid class. 'Guid' is the type name. If you've not changed your IDE colours, it'll show up in a sort of duck-egg blue to indicate it is a type. What this method returns is a Guid instance (i.e. an object of type Guid, not the type itself) that has been poplated with a unique value via one of the GUID generation algorithms.