why getter and setter is used code example

Example: Getter and Setter methods

import java.util.Scanner;
class Student {
   private String name;
   private int age;
   Student(){
      this.name = "Rama";
      this.age = 29;
   }
   Student(String name, int age){
      this.name = name;
      this.age = age;
   }
   public void display() {
      System.out.println("name: "+this.name);
      System.out.println("age: "+this.age);
   }
}
public class AccessData{
   public static void main(String args[]) {
      //Reading values from user
      Scanner sc = new Scanner(System.in);
      System.out.println("Enter the name of the student: ");
      String name = sc.nextLine();
      System.out.println("Enter the age of the student: ");
      int age = sc.nextInt();
      Student obj1 = new Student(name, age);
      obj1.display();
      Student obj2 = new Student();
      obj2.display();
   }
}