Microsoft Flow is the preferred tool for designing and executing workflows in the Office 365 environment, including SharePoint Online. Flow works on a series of triggers and actions. Triggers are events that are used to start a flow and can be event-driven (for example, when a document is uploaded), scheduled, or manually initiated. Flow's power is that it is not limited to only interacting with the SharePoint Online environment. Flow has triggers for things such as an item being uploaded to a OneDrive or DropBox site or a Tweet with a particular hashtag posted on Twitter, and can then take actions such as updating a SharePoint list, posting a tweet, or sending an email.