Reference:
https://docs.microsoft.com/en-us/dynamics365/customer-service/define-service-level-agreements

Reference:
https://docs.microsoft.com/en-us/dynamics365/field-service/set-up-time-groups

Explanation:
Box 1: 25
Customers must have contracts that allow them to call Lamna Healthcare 10 times a year for help.
In addition to the 10 free calls, customers must be able to send 15 emails a year for support.
If you want to restrict support through the phone channel to 80 hours and email to 20 hours, create individual entitlement channel records and add their total terms.
Box 2: Entitlement Channel
The Entitlement Channel section specifies the support channel through which the customer can reach the organization and seek support.
Use this section to define the channels your customers are entitled to and track the customer support term for each channel. For example, you can add phone and email as the channels through which you'll offer support.
If you want to restrict support through the phone channel to 80 hours and email to 20 hours, create individual entitlement channel records and add their total terms.
Box 3: Auto-calculate
The remaining term is auto-calculated and shows the total number of hours or cases remaining for the customer's entitlement.
Reference:
https://docs.microsoft.com/en-us/dynamics365/customer-service/create-entitlement-define-support-terms-customer