“Bar Mitzvah” literally means “son of the commandment” which actually means “one who adheres to the commandments.” “Bar” is “son” in Aramaic and “Bat” is “daughter” in Aramaic, which used to be the vernacular of the Jewish people. “Mitzvah” is the word for “commandment” in both Hebrew and Aramaic. Technically, the term refers to the child who is coming of age, and it is strictly correct to refer to someone as “becoming a bar (or bat) mitzvah.” However, the term is more commonly used to refer to the coming of age ceremony itself, and you are more likely to hear that someone is “having a bar mitzvah.”
Under Jewish Law, children are not obligated to observe the commandments, although they are encouraged to do so as much as possible to learn the obligations they will have as adults. At the age of 13 (traditionally 12 for girls), children become obligated to observe the commandments. The Bar/Bat Mitzvah ceremony formally marks the assumption of that obligation, along with the corresponding right to take part in leading religious services, to count in a minyan (the minimum number of people needed to perform certain parts of religious services), to form binding contracts, and to testify before religious courts.
A Jewish boy automatically becomes a bar mitzvah upon reaching the age of 13 years, and a girl upon reaching the age of 12 years. No ceremony is needed to confer these rights and obligations. The popular Bar/Bat Mitzvah ceremony is not required, and does not fulfill any specific commandment relating to this change in the child’s status. It is certainly not necessary to have a Bar/Bat Mitzvah in order to be considered a Jew! The Bar/Bat Mitzvah as we know it is a relatively modern innovation, not mentioned in the Talmud, and the elaborate ceremonies and receptions that are commonplace today were unheard of as recently as a century ago.
In its earliest and most basic form, a Bar/Bat Mitzvah is the celebrant’s first Aliyah to the Torah. During Shabbat services on a Saturday shortly after the child’s 13th birthday, the celebrant is called up to the Torah to recite a blessing over the weekly reading.
Today, it is common practice for the Bar/Bat Mitzvah celebrant to do much more than just say the Torah blessing. It is most common for the celebrant to learn and chant the entire Haftarah portion from the Prophets. In some congregations, the celebrant leads part of the service, or leads the congregation in certain important prayers. The celebrant is also generally required to give a D’var Torah (speech/sermonette).
It is important to note that a Bar/Bat Mitzvah is not the goal of a Jewish education, nor is it a graduation ceremony marking the end of a person’s Jewish education. We are obligated to study Torah throughout our lives.