The implements keyword is used in a class declaration to indicate that the class being declared provides implementations for all methods declared in the interface whose name follows the implements keyword.
public class Truck implements IVehicle
{
}
In the example above, the Truck class must provide implementations for all methods declared in the IVehicle interface.
The Truck class is otherwise independent; it may declare additional methods and variables and may extend another class.
A single class may implement multiple interfaces.