Prerolls, postrolls, and midrolls are all forms of secondary content that intentionally interrupt the primary content that a viewer is intending to watch.
As the name suggests, postrolls play after the main content is finished. Postroll ads do occur on some websites, but are less common because users will often abandon the page when the content is finished. Postroll bumpers are sometimes used to end the video with a logo or a prompt to share the content.
