The tags, along with other information such as title, cover image, author, date (and perhaps abstract) are displayed in an Infobox on the top right. (The abstract may best be presented in its own box, below it).
Most tags are passed to the system through the infobox instantiation box, though some are controlled by the infobox system. A good example are status tags (Baseline/Peer Reviewed/..) since we do not want the author controlling them. This means the Infobox has access to the list of article names that are "Baseline", and the template for the infobox is protected.