Soa service API ideal for common services like exchange money.
Service could become industry standard and money houses provide
implementations in their various languages.
Qos elements security, reliable messaging.
Component based philosophy is bring oo concepts to component level,
soa brings these loosely coupled components together.
The components can be built in a layered architecture too so all
bussiness util comes sit in same layer ie address book service can
then be reused by other layers.