Web API: Need to understand a web api attribute routing

Question

got the code from this url http://stackoverflow.com/questions/21704505/how-do-i-use-webapi-rest-correctly-when-other-params-are-needed?rq=1

 

i am new in web api attribute routing

[Route("customers/{customerId}/orders")]
public IEnumerable<Order> GetOrdersByCustomer(int customerId) { ... }

or

[Route("customers/{customerId}/orders/{orderId}")]
public Order GetOrderByCustomer(int customerId, int orderId) { ... }

 what is the meaning of 1st and 2nd route ?

 

how the first and second url will look like  please add the same url for both above action ?

 

thanks