Netflix is a subscription video streaming service built around films, TV series, documentaries, specials, and original programming. In practical terms, it is sold as paid plans with different feature tiers rather than a permanent free product, so the product is not just the catalogue itself but the way the service packages access, apps, features, and account rules around that catalogue.
The point most consumers need early is that Netflix is an access service, not a permanent ownership product in the old retail sense. You are paying for the right to use the service on supported devices under the current plan rules, not buying a library that sits outside the platform altogether.