Apple One+ Subscription

I think you are asking about the content in Apple TV+ and what is included in a subscription to the service, and what is not included.

Apple TV+ is included with the Apple One subscription.

Apple TV+ is the video streaming service from Apple and all this content is part of the subscription. The Apple TV app also offers content from other providers. This content is not Apple's, is not part of Apple TV+ subscription, and requires payment for viewing.

Read

Bundle Apple subscriptions with Apple One - Apple Support

Apple TV+ - Overview

Titles for buy or rent are not part of the Apple TV+ catalog. Instead they are from the iTunes Store catalog, for which no subscription is required, just a per title payment.