Agent Pools vs Parallel Jobs in Azure Devops

https://statathlon.com/historical-predictive-analysis-for-the-100m-sprint-race/

Agent pools and Parallel jobs

The difference between the agent pools and the parallel jobs are these parallel jobs will run on the agent pools.

So if you are using your own agent pool and you need to run parallel jobs, you would need to purchase parallel jobs separately which costs $40 USD per month.