What is a "driver class"?

A driver class in programming is a special class whose main purpose is to execute or test other classes. It usually contains the main method (in languages like Java or C++) and acts as the entry point of a program. Instead of containing the actual business logic, the driver class is responsible for creating objects, calling methods, and showing how different parts of the program work together.

Here’s what makes a driver class useful:

• Entry Point: In Java, the driver class typically has the public static void main(String[] args) method, which serves as the starting point of the program.
  
• Testing: Developers often use a driver class to test other classes. For example, after writing a Student class, you might write a StudentDriver class to create student objects and test their methods.
  
• Separation of Concerns: By keeping the logic in one class and the execution/testing in another, programs become cleaner and more organized.
  
• Demonstration: A driver class is helpful when demonstrating how different classes interact, making it easier to understand the program flow.
  

Example in Java:

public class Student {
    String name;
    Student(String name) {
        this.name = name;
    }
    void display() {
        System.out.println("Student name: " + name);
    }
}
public class StudentDriver {
    public static void main(String[] args) {
        Student s1 = new Student("Alice");
        s1.display();
    }
}

In short, a driver class acts as the “controller” that drives the execution of your program. It doesn’t usually hold logic itself but instead coordinates how the other classes and methods are used.