These are the terms used in this documentation. Windows Server 2003 or Server 2008 R2 resources will use varying terms.
Server Cluster: A server cluster is a group of two or more servers working together to provide applications or services to clients. A server cluster provides failover support should a server in the cluster fail. Responder can use a server cluster to provide failover support for the Responder services (i.e., Data Services, Archive Services, Prediction Services). A server cluster may also be referred to as a cluster.
Group: Each virtual server in the cluster is represented by a group. When failover occurs, the entire group will failover. This document will always refer to the item that represents a virtual server in the cluster as a group.
Resource: Each group consists of resources that indicate information such as physical address, IP address, message queuing and network name.
Node: A node represents a physical server in the server cluster. The names of your nodes can correspond with the names of the servers they represent.