Question

The boundaries of a thermodynamics system are physical boundaries such as walls or pistons

Answer 1

It may bhi physical boundary or an imaginary boundary created to study a perticular part.

The system boundary is a conceptual line that divides the system that you want to study from 'everything else'. It is useful to think of a system's environment as being made up of those things that are not part of the system, but can either affect the system or be affected by it.