According to the Open Access website "Open access is a publishing model for scholarly communication that makes research information available to readers at no cost, as opposed to the traditional subscription model in which readers have access to scholarly information by paying a subscription (usually via libraries)."
Summon is a search engine that searches for articles, eBooks, and other resources using keywords. Summon searches MOST, but not ALL of our resources. If you need more specific or focused results, try searching the individual databases.