A conference proceeding is the published record of a conference, congress, symposium, or other meeting sponsored by professional association or society. Proceedings typically include abstracts or reports of papers presented by the participants. 

Generally speaking, papers presented at conferences are working papers; they are not peer-reviewed journal articles. Some conference papers may evolve into peer-reviewed publications in the future, while others will not. 

Some library databases make it easier to search for conference proceedings through search limiters.  Look for terms like "Conference papers", "Conference notes", or "Conference materials".