1. 'use client' defines the boundary between server and client code on the module dependency tree, not the render tree.

• A component is only a Client Component if it declared 'use client' or imported by another Client Component.
• If the component is not directly imported nor called the component by another Client Component, then it is still a Server Component, even though it could be rendered inside a Client Component.
• The takeaway is that a parent-child render relationship between components does not guarantee the same render environment.

2. A component can be both a Server or Client component. It depends on where it is being imported from.

https://nextjs.org/docs/app/building-your-application/deploying#docker-image