why do we use methods in java programming code example

Example 1: java method

public class Main {
  public static void main(String args[]) {
    SayHi();
    
    int sum = AddNums(5, 6);
    System.out.println(sum);
  }
  
  public static void SayHi() { //This method has no return value
    System.out.println("Hi!");
  }
  
  public static int AddNums(int a, int b) { //This method has a return value
    return a + b;
}

Example 2: what is a method example in java

public int addNum(int num1, int num2) {
  total = num1 + num2;
  System.out.println("Total: " + total);
}