how class can be a reference type

class Student
{
 public string StudentName = string.Empty;
 public int Age = 0;
}

class StudentManager
{
  public void ManageStudents()
  {
    Student student1 = new Student(); // Creating Instance1;
    
    student1.Name = "Student 1"; 
    
    Student student2 = new Student(); // Creating Instance2;
    student2 .Name = "Student 2"; // Instance 2 created 

    //Instance1 and Instance2 are different because we create 2 different memory block for the student class using the new Keyword
    //Now see the magic of Reference type
    int age = 10;
    Console.WriteLine(student1.Age);    
    ChangeStudentName(student1,age);  
    Console.WriteLine(student1.Age);     
  }
 
  private ChangeStudentAge(Student student,int newAge)
  {
     student.Age= newAge;
     newAge = 100;
    //the variable student is local to this method but any changes made to the student instance will get effected on the original student1 instance inside the 'ManageStudents' method. but any changes made to the 'newAge' int variable does not change the age variable defined in the ManageStudents method. 

   //Because student is reference type object and int is a value type object
  }
}