When linking Continuing Course Enrolments Overview to represent student's course work that spans over multiple terms/semester/school years, the Successor Course Enrolment is the enrolment that represents the continuation of the course work that student has started in an earlier section.
Generally the student will complete the course work in a Successor Course Enrolment, and the school will submit the course mark for all the work the student has done in the Continuing Course Enrolment 'chain' on the final Successor Course Enrolment.
See the Continuing Course Enrolments Overview overview for more details.