Most of the time you will create string as literals.
let str = "Hello";
But, like an Array, you can create a string by using the String constructor.
let str = "Hello";
console.log(str);
console.log(typeof(str));
str = new String("Hello");
console.log(str);
console.log(typeof(str));
str = String("Hello");
console.log(str);
console.log(typeof(str));
It's interesting to look at the output of these three cases in the debugger. The second case shows an object with an internal array that has a length of 5. The other two cases return a literal string.
You can use the String constructor to convert a different type to a string. It doesn't work to convert an object, except for an array of primitive types.