By the 20th century Jews lived in places as different as New York and Casablanca, and as far apart as Buenos Aires, Warsaw, and Jerusalem - in cities, in villages, and on farms. Some lived and worked in religiously diverse areas and others remained in Jewish-dominated communities. These different populations reflected the diversity of Jewish lives. However far apart they were located, these communities shared several characteristics. Often excluded from the society around them, they established their own organizations, schools, hospitals, charities, and clubs. Even as Jews increasingly participated in the surrounding culture, Jewish organizations endured. Religious institutions, rituals, and cultures linked Jewish communities past and present. At the heart of each community is a rabbi and synagogue. And observant Jews, no matter where they live, need a shohet (kosher butcher), mohel (circumciser), and mikveh (ritual bath).