The Torah is like the Jewish bible. It tells all the stories of Judaism. It is written in Hebrew which is the Jewish language. Torah is usually chanted in the traditional Jewish trope, or system of chanting. The Bar or Bat Mitzvah chants from the Torah on the occasion on their Bar or Bat Mitzvah.
What it means:
When you have a Bar of Bat Mitzvah, it means that you are counted as an adult in the Jewish community. You are expected to live up to the responsibilities of your religion. It usually occurs around the age of 12 or 13.
What happens in a Bar of Mat Mitzvah:
The person having their Bar of Bat Mitzvah, leads the service. They lead all the prayers and even do a commentary on what they think about their Torah portion. The person will also chant from the Torah and Havtorah, which is a commentary from the ancient prophets.