A dynamic cluster is same like a static cluster except that WebSphere will control the no of active instances for an application, their placement by using service policies and work load demand.
below diagrams are for your understanding of the new features of the WAS v8.5. I tried to simplify them and in that process some details are lost. However i’ll write a separate posts on each of the new features.
How WAS v8.5 is made ?
Application Edition Management
On-Demand Router (ODR)