Right-click a slide and select "Format Background."
This is the classic "hero" background. You will rotate images using JavaScript. how to make a slideshow background
The you're using (e.g., PowerPoint, Keynote, Canva) Right-click a slide and select "Format Background
The first step in creating a background is determining the tool and format. Whether you are using PowerPoint, Google Slides, or Keynote, the process usually begins with the "Slide Master" or "Theme" settings. This is a crucial step for efficiency; by designing the background on the master slide, you ensure that every subsequent slide maintains a uniform look without requiring you to manually re-format each one. Consistency is the hallmark of professional design. Before adding any visual elements, decide on the aspect ratio—standard (4:3) or widescreen (16:9)—to ensure your background image or color fills the canvas without stretching or leaving black bars. Whether you are using PowerPoint, Google Slides, or