This is related to their mobile operating systems and services. Although people have fun in comparing both of them but their fundamental strategy is different altogether. I would like to explain them in most simple terms as follows.
Apple
Apple builds services around its devices. Their main source of income are their devices and hardware. Their services like iTunes, App Store, Apple Maps, iCloud and Siri are just those things which make their devices appealable to buyers.
Google builds products (like Android) around its services. Their primary source of income is advertising. They created Android to bring more and more users to their services like GMail, Google Search, YouTube & Google Maps.
Apple builds services around its devices while Google builds products around its services.
Although these companies have been so successful in their strategies that even their secondary sources or what you can refer to as, supporting products are profitable now.