I search about Why .NET String is immutable? And got [this](https://stackoverflow.com/a/3428743/1968030) answer:

> 
> Instances of immutable types are inherently thread-safe, since no
> thread can modify it, the risk of a thread modifying it in a way that
> interfers with another is removed (the reference itself is a different
> matter).
> 
> 
> 

So I want to know How Instances of immutable types are inherently thread-safe?