Teachers schedule recurring classes when they want to offer the same class multiple times, at regular intervals. They may want to do this for single classes, or to set up multiple class sessions inside a course.
For example, a teacher might schedule the same class on the first of every month for the next twelve months. When set up as a recurring class, the teacher only has to do this once, since classes can recur for a year. Otherwise, they would have to enter the class twelve times.
There are benefits to learners as well. Recurring classes let learners look ahead through the schedule, and determine which class session suits their calendars. Then they can sign up and plan in advance.