Java方法重载和方法重写的区别到底在哪?

/*
这里只是简单的示例一下,Food Snack没有给出,意会一下即可.
*/
public class Demo{
	public void eat(Food food){
		System.out.println("今天正常吃饭!吃了" + food.name);
	}
	
	public void eat(Snack snack){
		System.out.println("今天想吃零食!吃了" + snack.name);
	}
	
	public int eat(){
		int money = 10;
		System.out.println("今天喝西北风!但是省钱了,返回省钱的数目");
		return 10;
	}
	
	//public void eat(){
	//	int money = 10;
	//	System.out.println("今天喝西北风!但是省钱了,返回省钱的数目");
	//}
}

public class Father {

    private boolean canRun = false;

    public boolean isCanRun() {
        return canRun;
    }

    public void setCanRun(boolean canRun) {
        this.canRun = canRun;
    }

    public void walk(boolean canRun){
        if(canRun){
            System.out.println("父亲尽力跑啊跑!");
        }else{
            System.out.println("父亲老了,只可以走路!");
        }
    }
}

public class Son extends Father{

    boolean canRun;

    public Son(boolean canRun){
        this.canRun = canRun;
    }

    @Override
    public void walk(boolean canRun) {
        if(canRun){
            System.out.println("儿子可以跑!");
        }else{
            System.out.println("儿子也只能走!");
        }
    }
}

public class Test {
    public static void main(String[] args) {
        Father father = new Father();
        Son son = new Son(true);
        father.walk(father.isCanRun());
        son.walk(son.canRun);
    }
}

public class Test {
    public static void main(String[] args) {
        Father father = new Son(true);
        System.out.println(father.isCanRun());	// false
        father.walk(father.isCanRun());			// 儿子也只能走!
    }
}