How does Next Step in Action Buttons differ from Next in Step Completion Rule?

Next Step in Action Buttons	Next in Step Completion Rule
In Action Buttons for Flows, the Next Step is an action that you can add to a custom button in a Flow step. When you add Next Step as Action Buttons in Flows it helps your users to move to the desired next action in the Flow.	In Step Completion Rule, the rule On click of “next” button is not a custom button, rather a rule that enables end users to move to the immediate next step in the Flow. Info: Step Completion Rule is available in both Attached to element and Free-floating step types in Flows.
For example, if you want your users to “Submit Feedback or “Start Trial” to submit feedback or begin a process from the current Flow, use the desired call-to-action text (in this case, use Submit Feedback or Start Trial) as the Next Step action. Info: Action Buttons are available in both Attached to element and Free-floating step types in Flows.

Next Step in Action Buttons

Next in Step Completion Rule

In Action Buttons for Flows, the Next Step is an action that you can add to a custom button in a Flow step. When you add Next Step as Action Buttons in Flows it helps your users to move to the desired next action in the Flow. Next on Action Buttons

In Step Completion Rule, the rule On click of “next” button is not a custom button, rather a rule that enables end users to move to the immediate next step in the Flow.

Next as a completion rule

Info:
Step Completion Rule is available in both Attached to element and Free-floating step types in Flows.

For example, if you want your users to “Submit Feedback or “Start Trial” to submit feedback or begin a process from the current Flow, use the desired call-to-action text (in this case, use Submit Feedback or Start Trial) as the Next Step action. CTA example in action buttons for Flows

Info:
Action Buttons are available in both Attached to element and Free-floating step types in Flows.

Here’s GIF showing the difference between Next in Action Buttons and On click of “next” button in Step Completion Rule.

Difference between Next button and Next in rule