There is nothing sacred about electrons being called negative charge and protons positive charge.Itâs just a convention. You, can very well call electrons as positive charge and protons as negative charge!
Single Node or Psuedo-Distributed Cluster is the one in which all the essential daemons (like NameNode, DataNode, JobTracker and TaskTracker) run on the same machine. The default replication factor for a single node cluster is 1. A single node cluster is basically used to simulate a full cluster like environment and to test hadoop applications and unlike the Stand-alone mode, HDFS is accessible in this.
Node in a Failover Cluster. A failover cluster node is a server that is a member of a failover cluster. When a node is online, it is an active member of the cluster and can own and run clustered services and applications, honor cluster database updates, contribute votes to the quorum algorithm, and maintain heartbeats.