Sometimes you may need to create a large set of pages that share the same structure but have differing content. Through the standard AEM interface, you would need to create each page, drag the appropriate components onto the page and fill each of them in individually.
With scaffolding you can create a form (a scaffold) with fields that reflect the structure you want for your pages and then use this form to easily create pages based on this structure.
Although there is a Scaffolding mode available, the maintenance and creation of scaffolds as well as creating new pages from scaffolds is done in the classic UI. See Scaffolding in the classic UI authoring documentation for details.