Your layout is how and where content is placed on any given page or section of your website or application. Multi-column, 2-column, single-column formats for sections, what content to put where, etc. Before Responsive Design and our modern framework, we designed templates that had locked/fixed-place positions for content. Terms like "subpage" would classically refer to a set layout with the same positions on every page.

Content is your text, images, video or item data. For simple business websites, this is usually just the copy for your pages or images and videos for sections and widgets throughout your website. For applications, item data might be your product SKUs, model numbers and categories--or the map coordinates for a location. Generally, applications like product catalogs or location directories, events or downloads can be updated with JSON or csv spreadsheet import.