Microsoft 365 is a set of subscription services (including Microsoft Office) offered by Microsoft.
These are offered to RWTH - students and employees, each with different scope and licenses.
RWTH employees may use M365 for business use on their business devices.
Students may use the licenses for student self-administration and communication.
Accordingly, the M365 service is offered separately for the respective groups (students, employees) in different clients (tenants), which entails different registration and login procedures.