Flow Navigation can be added to flow screen components to provide a way to specify what kind of navigation should take place upon things like button clicks.

There are three kinds of Flow Navigation:

  1. Move the Flow (equivalent to clicking Next, Previous, or Finish)
  2. Load a Web URL into another tab (Lightning Experience only)
  3. End the flow by replacing it with another Salesforce page (Lightning Experience only)

When a component has Flow Navigation added to it, it inherits the following attributes:

destinationRecordIdIf a recordId is specified here, navigation will be to a particular record page. 
destinationObjectNameIf the name of an object is provided, the navigation will be to the Object, and the specific target page can be specified in the separate ActionName attribute
destinationPageNameNavigation will be to a named page. Allowable values are home, chatter, today, and dataAssessment
destinationTabNameNavigation will be to a tab page.
destinationWebUrlNavigation will be to a web page. This usually will open in a separate tab, leaving the flow alone, while the other navigations result in immediate termination of the flow. Each of these approaches has ramifications.
actionNameValid values include home, list, and new and the default is list.  Applies to destinationObjectName, in which case  and to destinationRecordId, in which case the valid values are  clone, edit, and view and the default is view.
destinationFlowTransitionValid values are Next, Previous, Finish. More info.

Determination of which destination to take is implicit: the navigation code expects either 0 of the destination attributes to be passed in (in which case no navigation will occur) or 1 will be passed in. If you specify two or more, an error message will appear.

More information on the underlying Lightning Navigation technology is available here.