Power Virtual Agents lets you create powerful chatbots that can answer questions posed by your customers, other employees, or visitors to your website or service.
Use Dynamics 365 Customer Service to:
* Track customer issues through cases
* Record all interactions related to a case
* Share information in the knowledge base
* Create queues and route cases to the right channels
* Create and track service levels through service-level agreements (SLAs)
* Define service terms through entitlements
* Manage performance and productivity through reports and dashboards
* Create and schedule services
* Participate in chats
* Manage conversations across channels
Reference:
https://docs.microsoft.com/en-us/power-virtual-agents/fundamentals-what-is-power-virtual-agents
https://docs.microsoft.com/en-us/dynamics365/customer-service/overview