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.
Isolated Groups. Clusters are isolated groups of data points. Line plots, which are one of the ways to represent data sets, are lines with x marks placed above specific numbers to depict their frequency of occurrence in the data set. A cluster is depicted as a collection of these x marks in a small interval or data subset.