[Basic Java] What happens if you declare String Class and change what you declare?

When using strings in Java

String str1 = "hello"; We have learned that is declared in the constant domain.

But if you declare it in the constant field, String str1 = "hello"; String str2 = "hello"; If you point to the same hello like this, str1 and str2 point to the same position, and while doing this, I had a question.

If I write [str1 = "h";] under [String str1 = "hello";] str1 does not change hello to h in the existing position, but creates a new place called h in the constant region?

Thank you for your answer ^{^}