In a traditional Shabbat Torah service, seven people are called for aliyot.
An aliyah is the honor of being called to the Torah, and the word also describes the act of going up to the reading platform. On Shabbat morning, Jewish law traditionally assigns seven aliyot, followed by a final reading for the person who chants the maftir passage. The service then includes the haftarah, the prophetic reading.
A bar or bat mitzvah celebrant commonly receives one of these honors or may read a Torah portion. The exact role varies by congregation and by the student’s preparation. In some communities, the celebrant chants the entire portion; in others, the student reads only selected verses or leads another part of the service.
The number seven applies specifically to the standard Shabbat morning Torah reading. Weekday services traditionally have three aliyot, while festivals generally have five and Yom Kippur morning has six.