The word 志愿者 is formed by combining three individual characters, each contributing to the overall concept. 志 (zhì) conveys "will" or "aspiration", 愿 (yuàn) means "wish" or "desire", and 者 (zhě) is a nominalizing suffix that means "the one who". Therefore, when combined sequentially, they construct the idea of "one who acts out of their own willing aspiration", directly picturing a person whose actions are motivated by personal commitment and desire, which is the core meaning of a volunteer.