A tutorial is a teaching session given to one student or a small group of students. If you are stuck in a class, you could use a tutorial.
Teachers lead classes, but tutors are educators who also help students, usually one-on-one. Tutors don’t give grades: they just try to help or coach students. A session given by a tutor is called a tutorial. A tutorial could be a one-on-one session in a tutoring center or elsewhere. A tutorial could also be a small group led by a tutor, in which the tutor helps the whole group with math, history, or another topic.