I'd like to see this for footers; have the footer at the bottom of the browser if the content is too small, or the bottom of the webpage if the content is large

I'd like to see this for footers; have the footer at the bottom of the browser if the content is too small, or the bottom of the webpage if the content is large enough for the user to scroll. After skimming the video, I'm not sure if this would be possible with "position: sticky".