This is the 13939th most frequent German word.
freiwilliger
"Freiwilliger" means "volunteer" in English.
In this sentence, 'Freiwilliger' is used as a noun referring to a person who volunteers or offers their services willingly.
Er ist ein Freiwilliger, der gerne in seiner Freizeit hilft.
He is a volunteer who likes to help in his free time.
Here, 'freiwillig' is an adjective describing the nature of the participation as being voluntary or done by choice.
Die Teilnahme an dem Workshop ist freiwillig.
Participation in the workshop is voluntary.
In this sentence, 'freiwillige' modifies 'Helferin,' indicating her role as a helper characterized by being voluntary or not obligatory.