Azure DevOps Pipeline, Jobs and agents

azure resource managing templates -- json
pipepline -- yaml

Agent Pool Jobs
-Run on a dedicated or assigned system contained within a pool.
-The capabilities of the system determine the jobs which can be run
-JObs can only be run if the pool has an agent available.

https://docs.microsoft.com/en-us/azure/devops/pipelines/process/phases#agent-pool-jobs

Server JObs
-Jobs are executed directly on the Azure Devops(or TFS) server
-Jobs are executed without an agent,so range of jobs are limited.
-use 'pool:server' or 'server:true' to use server jobs in the pipeline yaml file.

Using Agent Demands
-specifies what capabilities that agent must have
-linked to OS,apps and versions.
-multiple demands can be specified for each job
-demands can be asserted manually or automatically

https://docs.microsoft.com/en-us/azure/devops/pipelines/process/demands

Container Jobs
-Jobs can run inside a Docker container on windows and linux agents.
-Provides more control over the job execution environment
-Images can be retried from DOcker Hub or private registries