Which is better between a readonly modifier and a private setter?

Question

I\'ve been working on creating a class and suddenly a thought came to my mind of what is the difference between the two codes:

public readonly string Product         


        

Answer 1

The first one (using readonly) will mean that the object can't even modify its own field's value, once the object has been instantiated, and others can never modify it.

The second one (using private set) will mean that object can modify the value of its field after it's been instantiated, but others can never modify it.

I would use the former for something that you know will not change, and use the latter for something where the value may change, but you don't want others to change it.