Save will either insert or update the bean depending on its state.

Order order = new Order();
order.setOrderDate(new Date());
...
// insert the order
Ebean.save(order);

If the bean was fetched it will be updated...

Order order = Ebean.find(Order.class, 12);
order.setStatus("SHIPPED");
...
// update the order
Ebean.save(order);

Save and Delete will CASCADE based on the CascadeType specificed on the associated @OneToMany, @OneToOne etc annotation.

By default save and delete will not cascade so you need to specify a cascade type (such as the one on details below) for save() or delete() to cascade.

...
// the Entity bean with its Mapping Annotations
...
@Entity
@Table(name="or_order")
public class Order {

    ...
	// no cascading
    @ManyToOne
    Customer customer;

	// save and delete cascaded
    @OneToMany(cascade=CascadeType.ALL)
    List<OrderDetail> details;
	
	...

Note the @OneToMany(cascade=CascadeType.ALL) on the details property. This means save() and delete() will both casade from order to its order details.

...
// save the order ...  will cascade also saving the order details
Ebean.save(order);

Delete is very similar to save. Just call Ebean.delete();

...
Order order = Ebean.find(Order.class, 12);

// delete the order
// ... this will cascade also deleting the order details
// ... with either CascadeType.ALL or CascadeType.REMOVE
Ebean.delete(order);

Go here to see how Transaction demarcation is done.