What is the difference between Group and Private lesson?
When you book a private lesson you are booking the exclusive use of an instructor's time for yourself, your family, or your group of friends.
When booking a group ski school lesson, you are booking a space in a structured group lesson where you will be taught alongside other skiers/snowboarders of a similar ability level.
Neither group nor private lessons are better than the other - each choice has its own benefits as you can see here: https://www.skibro.com/blog/ski-lessons-group-lessons-or-private-instructor