What do the religious titles such as "Reverand", "Rabbi", "Father", "Pastor" and so on..signify?

rabbi means "teacher" in Hebrew. He is a teacher and spiritual guide to the congregation, but does not have to be present to lead a service- anyone can do that. Judaism is more of a home-based religion than Synagogue based, although services are an important part of Jewish life as we are instructed to pray with our community.