This text is written in HTMLContentBlock1 (within Editable Content). The block has then been placed on the template used for product pages (or whatever page is using the "1 Column" template in the Layout Manager). This means it appears on ALL pages using that template.
It means if updates are required, we can do it in one place and the changes will propogate everywhere. Use it for consistent text or on-page content. Or, use it for code / styling changes you wish to run on particular pages.
^^^ For this example, the section above has been styled with CSS input into the CSS Override area, meaning it applies site-wide. ^^^