If your presentation is rather lengthy, you may want to make it easier for your buyers to jump to different sections by enabling a Navigation Menu.
You can do so from your Presentation Settings when you're in the Presentation Editor.
When you turn this switch to "Show," every Section will have an additional checkbox option (in expanded Section Settings) to add a jump point to the Navigation Menu.
In this example, I've chosen to add the jump point to the Blurbs that precede the Products. This way, when the Buyer uses the navigation, they will see a heading and the Products below.
The name you give the Section will appear in the menu on the Buyer side so they can click and jump to that Section.