Explain method overriding vs method overloading.

Method Overloading:

• Multiple methods with same name but different parameters
• Compile-time polymorphism
• Same class can have overloaded methods
  Method Overriding:
• Redefining a method in derived class
• Runtime polymorphism
• Requires virtual in base class and override in derived class

// Overloading
public class Calculator
{
    public int Add(int a, int b) { return a + b; }
    public double Add(double a, double b) { return a + b; }
}
// Overriding
public class Shape
{
    public virtual double GetArea() { return 0; }
}
public class Circle : Shape
{
    public override double GetArea() { return Math.PI * radius * radius; }
}