Explanation
Box 1: Queue
Presales inquiries captured from the company website must be handled by dedicated teams for each country on a first-come, first-served basis.
The idea of FIFO queuing, also called first-come, first-served (FCFS) queuing, is simple: The first item that arrives at a router is the first item to be handled.
Box 2: Workstream
Presales inquiry handling must be maintained separately from support call handling.
A workstream is a container to enrich, route, and assign work items. The workstream is associated with a channel, such as live chat, voice, or case.
The workstream can belong to multiple channels of the same type, like multiple chat channels. In this case, all the conversations from these channels inherit the routing and work assignment settings of the workstream they belong to.
Box 3: Assignment ruleset
Support calls for specific HVAC systems must be directed only to their respective certified technicians.
Assignment methods determine how a work item is assigned. You can use the out-of-the-box assignment methods or build custom assignment rules by configuring the prioritization rules and assignment rulesets The following assignment methods are available out of the box:
* Highest capacity: Assigns work item to the agent with the highest capacity, among those who have the skills identified during the classification stage, and who have the presence as specified in the allowed presence option of the workstream. In this assignment method, the work items are prioritized in the first in first out manner, that is, the work item that was created first is assigned first. If more than one agent is available with the same capacity, the work item is assigned randomly.
* Round robin
Reference:
https://www.sciencedirect.com/topics/computer-science/first-come-first-served
https://docs.microsoft.com/en-us/dynamics365/customer-service/create-workstreams
https://docs.microsoft.com/en-us/dynamics365/customer-service/assignment-methods

Explanation
If the start and end date of the entitlement fall in the future, the status of the entitlement is set to Waiting. On the start date, the status automatically changes to Active. If the end date is in the past, the entitlement is set to Expired.
Reference:
https://docs.microsoft.com/en-us/dynamics365/customer-service/create-entitlement-define-support-terms-custom

Explanation
Box 1: Two
You must create two types of Omnichannel queues: regular and escalated.
Box 2: Add a routing rule for a push on owner assignment in Omnichannel Tickets assigned to a representative must be automatically placed in that representative's queue.
A customer initiates a conversation from the portal, and the conversation reaches the Omnichannel system.
Now, based on the routing rules condition defined in the routing system, it starts routing the conversation to the appropriate queues.
When the conversation reaches to the queues, the work assignment system assigns the conversation based on triggers.
Reference:
https://docs.microsoft.com/en-us/dynamics365/customer-service/routing-work-distribution-oca