Difference between the Constructors and Methods

// Java Program to illustrate constructor

import java.io.*;

class Geek {
    int num;
    String name;

    // This would be invoked while an object
    // of that class created.
    Geek()
    {
        System.out.println("Constructor called");
    }
}

class GFG {
    public static void main(String[] args)
    {
        // this would invoke default constructor.
        Geek geek1 = new Geek();

        // Default constructor provides the default
        // values to the object like 0, null
        System.out.println(geek1.name);
        System.out.println(geek1.num);
    }
}

// Java Program to illustrate methods

import java.io.*;

class Addition {

    int sum = 0;

    public int addTwoInt(int a, int b)
    {

        // Adding two integer value.
        sum = a + b;

        // Returning summation of two values.
        return sum;
    }
}

class GFG {
    public static void main(String[] args)
    {

        // Creating an instance of Addition class
        Addition add = new Addition();

        // Calling addTwoInt() method
        // to add two integer
        // using instance created
        // in above step.
        int s = add.addTwoInt(1, 2);

        System.out.println("Sum of two "
                           + "integer values: "
                           + s);
    }
}