Open Access is type of publishing model, where the barriers to access scholarly research is removed. It means that it's "freely availability on the public internet, permitting any users to read, download, copy, distribute, print, search or link to the full text of these articles, crawl them for indexing, pass them as data to software or use them for any other lawful purpose…" - The Budapest Open Access Initiative
“Open Access is free online access to the outputs of publicly funded research. This includes journal articles, conference papers, theses, reports, and any other outputs. Because the research is publicly funded, the principle is to make the results freely and readily available to all. Readers can then access the material and use it for their own teaching and research purposes”. Source JISC
Discover more about Open Access, including approaches, types, and the benefits of Open Access.