Question { 4733 }

what is meant by multicast?

Answer

Multicast is used in networking.
it is used To transmit a single message to a select group
of recipients. in multicast, generally, we define a IP and
port for communication. we all send/receive message in form
of heartbeats to/from defined address.

Question { 7996 }

what is difference between business delegate and data access
object(dao)? in java?

Answer

Both are different design pettern. name drives their
functionality.
Business Delegate : it is used decouple presentation and
business layer. it avoids to intract presentation client to
understand your business services.

Data Access Object : DAO is used on database layer,
generally it is used to avoid database intraction by EJB or
Business Object. it is used to retreive and store data.
mostly I preferred, DAO is used with Value Objects