The druid is one of the many iconic classes in Dungeons & Dragons. Capable of assuming the forms of various animals, druids draw their power from the environment to cast a myriad of spells. Their subclasses are the druid Circles, representing different aspects of the natural world and different ways of interfacing with them.
Source:https://www.cbr.com/dungeons-dragons-best-druidic-circles-ranked/