Google is to Alphabet as iPhone is to Apple

Apple is often called a one-product company. And in that respect, Apple and the old, pre-Alphabet Google were alike. At Apple, it’s the iPhone that generates most of the company’s revenue. At Google, it’s search advertising.

But Apple and Google are different in a way that is even clearer today, now that Google has been restructured into a holding company (Alphabet) with two parts: Google (Google, YouTube, Android) and Others (Calico, Nest, Fiber, Google X, Google Ventures, Google Capital, etc.)

Think of the new Google, says Horace Dediu, now at the Clayton Christensen Institute, as Google A and Google B. From Dediu’s Asymco blog:

• Google A spends money. Google B collects money.
• Google B sends a check to Google A while Google A sends data to Google B (which then sells it on to advertisers and collects money).
• Google A communicates frequently with optimism and enthusiasm about the future. Google B remains quiet.
• Google A solves problems of humanity, Google B solves problems for advertisers.
• Google A has users, Google B has customers (to whom it sells users.)

Apple in the way it manages its resources is nothing like that. The company may burn its share of money—on stock buybacks, on fancy new headquarters, on Jony Ive projects that don’t pan out. But all its products and services—Watch, Music, iCloud, etc.—are aligned with its core business.

Apple is a singularly focused company. Google, we can now see even more plainly, is not.

Follow Philip Elmer-DeWitt on Twitter at @philiped. Read his Apple (AAPL) coverage at fortune.com/ped or subscribe via his RSS feed.