Hydration is the act of populating an object from a set of data http://framework.zend.com/manual/2.0/en/modules/zend.stdlib.hydrator.html

Using ZendDb’s TableGateway and HydratingResultSet to return rows as custom entity/model objects in ZF2

Zend Framework 2 : Using HydratingResultSet and ObjectProperty’s Hydrator

ZendDbResultSetHydratingResultSet