What is the difference between hard and soft coastal engineering?

Hard engineering is artificial, expensive and large scale coastal defences, where as soft engineering is more "in tune" with the environment and is considered ecologically friendly by using more natural techniques to defend coastlines. Hard engineering includes sea walls and groynes, and soft engineering includes beach nourishment, drainage and managed retreat. In most cases soft engineering uses natural resources available to us from the environment such as sediment from other beaches and letting current defences to fault and nature to take its natural course (managed retreat).