A mitzvah is a good deed. The plural of mitzvah is mitzvot.
Hassidic Jews are very Orthodox Jews. They approach the Torah (holy Jewish text) literally, and keep to many of the 613 mitzot (commandments). They keep kosher, don't drive or work or do many other things on the Jewish shabbat (fri evening til sat evening) and they attend Synagogue three times daily. They often have large families. The men study Torah and Talmud in great depth. The Hassidic movement is a very interesting one which developed as a following of a man known as the Baal Shem Tov. He taught that worship of G-d should be joyful, and he was revered by his followers. Within Orthodox Judaism, however, there are a number of other 'sects'. For a fascinating and beautifully written glimpse into the Hassidic world, I recommend THE CHOSEN, a novel by Chaim Potok. Wonderful book! ----------------------------------------------------------------------------------------------
It depends what part of the world you look at:In North America there are four main branches of Judaism:Orthodox, who are traditionalConservative, who try to walk a middle ground between Orthodoxy and ReformReform, which is liberal and places less emphasis on "rules" and more emphasis on personal responsibility.Reconstructionist, which is in some ways more traditional than Reform, and in other ways more liberal.(North America also has "humanist" congregations which generally do not believe in God, and unaffiliated synagogues.)In England there are 4 main typesOrthodoxMasortiReformLiberalIn Ireland and most other countries there are 2 main typesOrthodoxProgressiveIn Israel there is only one official typeOrthodox (However other denominations are now starting to get a foothold.)