Why do we need methods that return the value of a class field?

Question

Java

For example:

class Person{
    private String name;
    private int age;
    public Person(String n, int a){       
        name=n;
        age=a;
    }
    String getName(){return name;}
    int getAge(){return age;}
}

I often see that for each field a method is set that returns a value.
Why do they do it this way? After all, you can get this value by writing objName.atrName