Haredi Judaism is the most theologically conservative form of Judaism. Haredi Judaism is often translated as ultra-orthodox Judaism, although Haredi Jews themselves object to this translation. They simply refer to themselves as Jews, and they consider more liberal forms of Judaism to be unauthentic.
Chabad Lubavitch Hasidic Jews
Lubavitch Hasidism, which is generally presented through its organizational arm called Chabad, is a Jewish Haredi Hasidic movement. Chabad Lubavitch adherents are referred to as Lubavitchers or Chabadniks.

Orthodox Judaism believes that both the Written and Oral Torah are of divine origin, containing the exact words of God without any human influence.

Beliefs
Rambam's 13 Principles of Faith are an excellent summary of the core beliefs of Orthodox Judaism.

1. I believe with perfect faith that God is the Creator and Ruler of all things. He alone has made, does make, and will make all things.
2. I believe with perfect faith that God is One. There is no unity that is in any way like His. He alone is our God. He was, He is, and He will be.
3. I believe with perfect faith that God does not have a body. Physical concepts do not apply to Him. There is nothing whatsoever that resembles Him at all.
4. I believe with perfect faith that God is first and last.