A cluster is a logical grouping of one or more nodes. Even a single node launched alone is part of a cluster. A node can belong to only one cluster.
A cluster provides unified administration and distribution services for its nodes. That is, certain epadmin commands can be sent to the cluster's servicename to have effect on each node in the cluster.
Nodes in a cluster can run on different machine architectures and can have different versions of the same StreamBase Applications.
Clusters are dynamically created and removed as nodes are installed and removed. That is, clusters do not have an independent existence from their nodes.