How does "cost" differ from "opportunity cost"?

Opportunity cost concept is very important to the view of costs of economists. It is defined as the worth or value of a forgone activity or alternative when another item is chosen. It is a relative cost of one alternative in terms of the next best alternative. It is a vital economic concept which finds application a wide range of business decisions. Decision - making is usually overlooked by opportunity cost. Opportunity costs should often subjectively estimated by decision-makers.