Explanation
Personal access tokens (PATs) give you access to Azure DevOps and Team Foundation Server (TFS), without using your username and password directly. These tokens have an expiration date from when they're created.
You can restrict the scope of the data they can access. Use PATs to authenticate if you don't already have SSH keys set up on your system or if you need to restrict the permissions that are granted by the credential.
Reference:
https://docs.microsoft.com/en-us/azure/devops/repos/git/auth-overview

Explanation
When you run a pipeline on a self-hosted agent, by default, none of the subdirectories are cleaned in between two consecutive runs. As a result, you can do incremental builds and deployments, provided that tasks are implemented to make use of that. You can override this behavior using the workspace setting on the job.
Reference:
https://docs.microsoft.com/en-us/azure/devops/pipelines/process/phases

Explanation
Instead you should deploy an Azure self-hosted agent to an on-premises server.
Note: To build your code or deploy your software using Azure Pipelines, you need at least one agent.
If your on-premises environments do not have connectivity to a Microsoft-hosted agent pool (which is typically the case due to intermediate firewalls), you'll need to manually configure a self-hosted agent on on-premises computer(s).
References:
https://docs.microsoft.com/en-us/azure/devops/pipelines/agents/agents?view=azure-devops

Explanation
Create a service hook for Azure DevOps with Slack to post messages to Slack in response to events in your Azure DevOps organization, such as completed builds, code changes, pull requests, releases, work items changes, and more.
Note:
1. Go to your project Service Hooks page:
https://{orgName}/{project_name}/_settings/serviceHooksSelect Create Subscription.
3. Choose the types of events you want to appear in your Slack channel.
4. Paste the Web Hook URL from the Slack integration that you created and select Finish.
5. Now, when the event you configured occurs in your project, a notification appears in your team's Slack channel.
Reference:
https://docs.microsoft.com/en-us/azure/devops/service-hooks/services/slack

Explanation
No " Dependson are defined"
No "Mode is Apply and Monitor"
Yes "Configuration Mode FreqMin : 60 "
------
Configuration Mode Freq Min:How often, in minutes, the current configuration is checked and applied. This property is ignored if the Configuration Mode property is set to Apply Only.
https://docs.microsoft.com/en-us/powershell/dsc/managing-nodes/metaconfig?view=dsc-1.1
https://docs.microsoft.com/en-us/powershell/dsc/configurations/resource-depends-on?view=dsc-1.1