String literals vs String Object in Java

In java String can be created in 2 ways given below

1. String foo="Test";


2. String fooobj=new String("Test");

Everywhere it is mentioned about difference between these 2 ways of creating String. I want to know more about What are appropriate scenario's ,
where we should go for

  String foo="Test";
 

And when to go for

 String fooobj=new String("Test");  ?
 

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