Explanation

Box 1: Microsoft Teams
First up employees must be able to contact each other by using a secure system to ask and answer questions about medical cases.
Microsoft Teams key capabilities:
Connected
Secure
Managed
Collaborative and productive
Box 2: Microsoft 365 Business Voice
Workers must be able to communicate in near real-time with worker support agents.
Microsoft 365 Business Voice makes it easy for small and medium organizations to turn Microsoft Teams into a powerful and flexible telephone system. It's a replacement for traditional telephony providers and in-house phone systems that can be difficult and costly to manage.
Reference:
https://docs.microsoft.com/en-us/microsoft-365/solutions/empower-people-to-work-remotely
https://docs.microsoft.com/en-us/microsoftteams/business-voice/whats-business-voice