Who was the river nymph of Greek mythology?

In Greek mythology, river nymphs are known as Naiads, who are female spirits associated with fresh water bodies such as rivers, streams, and fountains. They are often depicted as beautiful maidens and are considered guardians of their respective waters. Naiads were believed to have the power to heal and were sometimes associated with fertility and nurturing. They played various roles in myths, including being romantic figures and companions to gods and heroes.