The Hobby plan is designed for personal projects and side projects. For production commercial applications, the Pro plan is the intended tier - it's built for professional developers and teams shipping to production, and includes team collaboration, higher resource limits, and longer log retention.

But can i leagaly use the hobby version to host a production backend for a commercial restaurant website that processes payments

There is no rule preventing you from running a commercial app on the Hobby plan, but it is designed for personal projects and does not include team collaboration, SLAs, or the higher resource limits that production workloads typically need. The Pro plan is the tier built for shipping to production.