This component is meant to exist within a Result Template. It allows to create a button/link inside the result list that opens a Quick View dialog box for a given result.
The Quickview Component has a default template. Most of the time, this is what you will want to use. The default template will include a title and a Coveo Component QuickviewDocument, but you can customize the content (see Choosing What to Display for the Quick View).
Detailed component information is available from https://coveo.github.io/search-ui/components/quickview.html.