The GradeCam ID is used when creating student accounts. To provide a further explanation is to understand that there are two IDs for students: 1)Student ID and 2)GradeCam ID.
Student ID is typically an ID from the school/district assigns. This usually a good choice because student ID's must be unique and cannot be reused unless you delete any student with that ID, in which you lose any data for the deleted student. You cannot edit a student ID once created. Numeric characters only.
GradeCam ID is another ID that is used by the software in the background. You can reuse and edit GradeCam ID's and edit the GradeCam ID. Many times the Student ID is used also for the GradeCam ID.
Hope this helps.