Difference between Bridge and Decorator pattern

i am learning software design pattern and want to know the difference between bridge and decorator pattern

 interface Iconcept
    {
        void action();
    }
    class concept : Iconcept
    {
        public void action()
        {
            Console.WriteLine("walking ");
        }
    }
    class decoratorA : Iconcept
    {
        Iconcept concept;
        public decoratorA(Iconcept concept)
        {
            this.concept = concept;
        }
        public void action()
        {
            concept.action();
            Console.WriteLine("with his dog");
        }
    }
    class decoratorB : Iconcept
    {
        Iconcept concept;
        public decoratorB(Iconcept concept)
        {
            this.concept = concept;
        }
        public void action()
        {
            concept.action();
            Console.WriteLine("in the rain");
        }
    }
    class client
    {
        static void Main()
        {
            Iconcept concept = new concept();
            concept.action();

            new decoratorA(concept).action();
            new decoratorB(concept).action();


            Console.ReadLine();
        }
    }

decorator pattern

definition:Attach additional responsibilities to an object dynamically. Decorators provide a flexible alternative to subclassing for extending functionality.

nowif we take this code for the decorator pattern, i have an implementation by the name concept and i am extending/decorating the implementation with new implementation class name as decoratorA and decoratorB

bridge pattern

definition: Decouple an abstraction from its implementation so that the two can vary independently.

i have a old implementation by the name concept and without doing any changes in the old implementation i am implementing a new implementation.

so what differentiates the two pattern