*Update (5/25/22)*: We have recently written an updated post on this topic. You can find that new blog post here: Automatically Send Responses to a SharePoint List Using Power Automate.
When enabled by an organization that has deployed Office 365, Microsoft Flow provides end-users with the ability to create automated workflows between applications and many different services using connectors. Microsoft applications and an ever-growing list of third-party services are available to link together. Microsoft Flow lets employees create simple to more complex workflows that can provide efficiencies for businesses around their workflow needs. It's an end-user option, that in most cases does not require a developer for workflows.