Conditions allow you to show additional steps in your workflow depending on the user's selection for an earlier step. They are set in the actual step you want to appear conditionally.
Commonly used to offer extra personalisation options. You set a question step with a YES/NO answer to the extra you want to offer. Then you create a step with the extra personalisation component and set it to only render if the user selects YES to the question step.
An example of conditions in use is on this knife workflow. At the start of the workflow a question is asked if they want to customize the knifes together or seperare. Depending what the user chooses, all steps that follow are conditional depending on their choice.