Prints is the deviantART Print Shop. It is a place where artists with either a Basic Prints account or a Premium Prints Account can sell their work. Anyone can browse this section of the website and buy artists' work.
If you're interested in learning more about Prints, please check the Prints Service FAQ. If this does not answer your question(s), contact the Prints Help Desk. The Help Desk for deviantART.com will not answer Prints related questions; on the Prints Help Desk will.