Pages within a survey can be organised into 'groups' (or sections 'sections'). These have no effect on the
survey as viewed by the candidate completing a survey, but they can make it easier for the author.
Consider the case where you have several pages that ask questions suitable for a male audience, and another ser of pages that
are suitable for a female audience. These pages can be collected into 'groups' and the entire group made 'conditional' on the
response to a gender question.
Entire groups can be moved en-masses withn a survey making some structural changes easier to achieve.