Orthodox, Progressive (also known as Liberal or Reform) and Conservative Judaism are the three major sects within the Jewish faith. Groupings within a major faith are common in Christianity, Islam, and Hinduism as well.
Orthodox Judaism focuses, as one might expect, on very traditional concepts of the faith. Scripture and worship are conducted in Hebrew and men and women are kept separate during services, with certain rituals being limited only to men. An essential tenant of the Orthodox sect is the interpretation of the Bible which ascribes to the concept of a Divine origin.
Progressive Judaism originated in the early 1800's as Jewish people in Europe wanted to live in harmony with their fellow citizens instead of being relegated to community life in slums. Ideologically, Progressive Jewish people believe in an ever-changing interpretation of the Torah and tries to find harmony between the important history and traditions of the Jewish faith and the realities and new understandings that come with modern life.
Conservative Judaism marries many of the concepts of the Orthodox and Progressive faiths. While Conservative Jewish people are socially liberal in their believes, they practice their faith conservatively. For example, while an Orthodox Jewish person would not even turn on a light on the Sabbath, Conservative Jewish followers allow the use of electrical appliances and even the use of a car if travelling to synagogue on a Sabbath day.