Simplified difference between Strategy and State pattern

i am learning patterns and i got confused when i came across state and startegy pattern. A simple googling took me to this stact overflow blog which made to get confused even more.

My simple quesiton is,

strategy pattern

public interface Istrategy {
        void algorithm();
    }
    public class add : Istrategy
    {
        public void algorithm()
        {
            Console.WriteLine("addition");
        }
    }
    public class multiply : Istrategy
    {
        public void algorithm()
        {
            Console.WriteLine("multiply");
        }
    }
    public class subtract : Istrategy
    {
        public void algorithm()
        {
            Console.WriteLine("subtract");
        }
    }
    public class context {
        public context(Istrategy strategy) {
            strategy.algorithm();
        }
    }
    public class client {
        static void Main() {
            new context(new add());

            Console.ReadLine();
        }
    }

state pattern

public interface Istate {
        void algorithm();
    }
    public class add : Istate
    {
        public void algorithm()
        {
            Console.WriteLine("addition");
        }
    }
    public class multiply : Istate
    {
        public void algorithm()
        {
            Console.WriteLine("multiply");
        }
    }
    public class subtract : Istate
    {
        public void algorithm()
        {
            Console.WriteLine("subtract");
        }
    }
    public class context {
        Istate state;
        public context(Istate state) {
            state.algorithm();
        }
    }
    public class client {
        static void Main() {
            new context(new add());

            Console.ReadLine();
        }
    }

in the above example, as per my understanding, i would take this as, passing a object to the context without any state saved is the strategy pattern and keeping the sate in the context is the state pattern.

is my understanding right?