School Management systems vary in size, scope, and abilities, from packages implemented in relatively small organizations to cover student records only, to enterprise-wide solutions, which aim to cover most aspects of the operation of large organizations and their online schools with significant local responsibility. Many systems can be staggered at different levels of functionality, by purchasing additional "modules" and usually formed by their home institutions to meet local needs.
Some of the SMS sovereign vendors can include in their products:
SMS usually provide portals for employees, teachers, parents, and students. A single sign-on with systems like Office365 for Education or Google G-Suite are considered almost mandatory features nowadays.
Additionally, SMS are lately fully integrated with external Learning Management Systems such as Moodle LMS. The SMS may be confused with the Learning Management System or the Virtual Learning Environment, where course materials, assignments, and evaluation tests can be published electronically. The reason is that SMS and LMS systems tend to overlap.
We can generally say that SMS cover mostly the administrative part of all processes in an academic institution whereas LMS cover mostly the learning & teaching part of the process.
Few software systems worldwide claim to be both SMS and LMS solutions at the same time