Jews are divided according to their beliefs and practices and according to their racial origins as either having roots in central Europe (Ashkenazi Jews) or Spain and the Middle East (Sephardi Jews). The main divisions of belief and practice are as follows:
Orthodox and 'Ultra-Orthodox' Jews

Orthodox Jews follow the original teachings and traditions of the faith closely.

They believe that the Torah and the Talmud were given by God directly to the Jewish People in and so they regard these documents as being God's actual words and of the highest authority in setting down the traditions and laws of Judaism

Orthodox Jews are the biggest group in most countries outside the USA.

"Ultra-Orthodox" Jews obey religious laws very strictly.

They live in separate communities and follow their own customs. To some extent they keep apart from the world around them.

The Ultra-Orthodox are one of the fastest growing groups of the Jewish people.

"Ultra-Orthodox" is not a term that Jews like very much and it is more acceptable to use the word "Haredi".

Conservative (also called Masorti) Jews fall somewhere between Orthodox and Reform Jews

Hasidic Jews

Hasidic Jews are a sub-group of Haredi Jews but the two terms are not interchangeable.

The essential elements of Hasidic Judaism are the high importance given to mysticism rather than learning and the reverence given to the leader of each of the many sects within the movement.

Hasidism began in Poland in the 18th Century. Hasidic Jews were almost completely wiped out in Europe in the Holocaust.

[Note: "Hasidic" is often spelled "Chasidic" and it's worth using both versions and a double "s" as well when doing online searches.]

Reform Jews and Humanistic Judaism

Reform Jews have adapted their faith and customs to modern life and incorporated the discoveries that modern scholarship has made about the early Jews. The Reform movement began in Germany in the early 19th Century.

They do not regard the Torah and Talmud as the actual words of God but as words written by human beings inspired by God.

Reform Jews believe that because the words of these texts were not directly given by God they can be reinterpreted to suit the conditions of a particular time and place. So for example men and women can sit together in a Reform synagogue when they would be rigorously segregated in an Orthodox synagogue.

However there are still many elements of Judaism that Reform Jews regard as unchangeable even though they may be less observant in many other areas of belief.

A particular feature of Reform Judaism is a strong belief in the importance of creating a just society and many Reform Jews have been in the forefront of political activism.

Reform Jews are the largest group in the USA where there is currently a gentle movement back towards traditional practices in worship.

Reform Judaism is strong in Britain where it is much more traditional than the USA version. The closest British equivalent to US Reform Judaism is the Liberal movement.

Reconstructionist and Humanistic Judaism are modern American movements. They are particularly attractive to those Jews who are uncomfortable with the supernatural elements of the other types of Judaism.