One of the core services in the 1EdTech OneRoster standard. This service is used for the exchange of rostering information i.e. the enrollment of Students on Classes. A rich set of data can be exchanged about Users (inc. Students and Teachers) and their Demographics, Classes, Courses, Enrollments, Academic Sessions (inc. Grading Periods and Terms) and Orgs (inc. Schools). The defined web service takes the form of JSON payloads exchanged by the communicating systems. At present this service is used extensively in the K-12/schools education sector.