Hi @RNabers Happy to share a few thoughts on this, in the simplest terms, a campaign is a collection of marketing assets you are grouping together towards a specific goal that you want to measure and a workflow is a tool to create automation, whether that contributes to a campaign or automates actions within the CRM, etc.
I like this HubSpot Campaign overview page, it does a really good job of simplifying it down, yet showing all of the capabilities with the various tools.
For a better understand of Workflows overall, I recommend this lesson from HubSpot Academy.