Which Fits Best: Determine which slide or slides need a video background. For this example, we're enhancing a song slide to resonate better with its auditory content.

Presentation Level: If you'd like to set a default background for the entire presentation, go to Presentation Settings and choose which type of background you'd like to edit (color, image, or video using link).

Section Level: If you're looking to change the look of slides in an entire section, click on the gear on the section back to the right. There, you will have the same options to change the background. This will only set a default background for that section. It does override the Presentation background if that is set.

Slide Level: Click into a slide to edit. You'll see the gear and this will open up the slide settings where you change the background.

Accessing Background Settings: Click on the gear icon within your presentation. This opens up the background options.

Choices at Hand: Here, you can choose from color backgrounds, image backgrounds uploaded directly from your computer, or video backgrounds via a link.

Integrating the Video: Since we're focusing on a video background, paste the relevant link in the provided space.

Looping: Once your video background is set and you're ready to present, the video will loop, ensuring a continuous visual treat without hiccups.

Preview: It's always a good practice to preview what the slide will look like during the actual presentation. Ensure the video syncs well with the slide's primary content and doesn't overshadow it.