Explanation:

When you swap deployment slots, Azure swaps the Virtual IP addresses of the source and destination slots, thereby swapping the URLs of the slots. We can easily revert the deployment by swapping back. Deployment slots are live apps with their own host names. App content and configurations elements can be swapped between two deployment slots, including the production slot. Deploying your application to a non-production slot has the following benefits: 1. You can validate app changes in a staging deployment slot before swapping it with the production slot. 2. Deploying an app to a slot first and swapping it into production makes sure that all instances of the slot are warmed up before being swapped into production. Reference: https://docs.
microsoft.com/en-us/azure/app-service/deploy-staging-slots

Technically, The finance department needs to migrate their users from AD to AAD using AADC based on the finance OU, and need to enforce MFA use. This is conditional access policy. Employees also often get promotions and/or join other departments and when that occurs, the user's OU attribute will change when the admin puts the user in a new OU, and the dynamic group conditional access exception (OU= [Department Name Value]) will move the user to the appropriate dynamic group on next AADC delta sync.
https://docs.microsoft.com/en-us/azure/active-directory/enterprise-users/groups-dynamic-membership
https://docs.microsoft.com/en-us/azure/active-directory/conditional-access/overview
https://docs.microsoft.com/en-us/azure/active-directory/authentication/howto-mfa-userstates
Topic 3, Contoso LtdOverview
Contoso, Ltd. is a manufacturing company that has offices worldwide. Contoso works with partner organizations to bring products to market.
Contoso products are manufactured by using blueprint files that the company authors and maintains.
Existing Environment
Currently, Contoso uses multiple types of servers for business operations, including the following:
File servers
Domain controllers
Microsoft SQL Server servers
Your network contains an Active Directory forest named contoso.com. All servers and client computers are joined to Active Directory.
You have a public-facing application named App1. App1 is comprised of the following three tiers:
A SQL database
A web front end
A processing middle tier
Each tier is comprised of five virtual machines. Users access the web front end by using HTTPS only.
Requirements
Planned Changes
Contoso plans to implement the following changes to the infrastructure:
Move all the tiers of App1 to Azure.
Move the existing product blueprint files to Azure Blob storage.
Create a hybrid directory to support an upcoming Microsoft Office 365 migration project.
Technical Requirements
Contoso must meet the following technical requirements:
Move all the virtual machines for App1 to Azure.
Minimize the number of open ports between the App1 tiers.
Ensure that all the virtual machines for App1 are protected by backups.
Copy the blueprint files to Azure over the Internet.
Ensure that the blueprint files are stored in the archive storage tier.
Ensure that partner access to the blueprint files is secured and temporary.
Prevent user passwords or hashes of passwords from being stored in Azure.
Use unmanaged standard storage for the hard disks of the virtual machines.
Ensure that when users join devices to Azure Active Directory (Azure AD), the users use a mobile phone to verify their identity.
Minimize administrative effort whenever possible.
User Requirements
Contoso identifies the following requirements for users:
Ensure that only users who are part of a group named Pilot can join devices to Azure AD.
Designate a new user named Admin1 as the service administrator of the Azure subscription.
Admin1 must receive email alerts regarding service outages.
Ensure that a new user named User3 can create network objects for the Azure subscription.

The New-AzResourceGroupDeployment cmdlet deploys an Azure Resource Manager template to a resource group. You can use this cmdlet to create a new resource group or update an existing one with the resources defined in the template. The template can be a local file or a URI. Then, References: [New- AzResourceGroupDeployment]

Every Azure AD directory comes with an initial domain name in the form of domainname.onmicrosoft.com.
The initial domain name cannot be changed or deleted, but you can add your corporate domain name to Azure AD as well. For example, your organization probably has other domain names used to do business and users who sign in using your corporate domain name. Adding custom domain names to Azure AD allows you to assign user names in the directory that are familiar to your users, such as '[email protected].' instead of
'alice@domain name.onmicrosoft.com'.
Scenario:
Network Infrastructure: Each office has a local data center that contains all the servers for that office. Each office has a dedicated connection to the Internet.
Humongous Insurance has a single-domain Active Directory forest named humongousinsurance.com Planned Azure AD Infrastructure: The on-premises Active Directory domain will be synchronized to Azure AD.
References: https://docs.microsoft.com/en-us/azure/active-directory/fundamentals/add-custom-domain