what is cluster in orientdb?

Clusterin OrientDB is used to store the group of documents, records or vertices. By default, OrientDB creates only one cluster in each class and in that one cluster which has the same name as of the class stores all the record of the class. In a database up to 32,767(2^15-1) clusters can be created.

A CREATE command is used to create a cluster in a class with a specific name. By default, only one cluster can be formed in a class, but multiple clusters can also be produced by spawning the records in various places