Open access resources refer to academic literature, such as peer-reviewed scientific papers, research reports and dissertations. Users can read, download, copy, spread, print and retrieve the full text of the works free of charge through the Internet, regardless of registration, copyright, time, space and economic conditions. The only restriction on users is that users should ensure the integrity of the author's works and indicate the corresponding citation information. OA resources are produced with the rise of OA movement in international academic circles, publishing circles and library and information circles, and use the Internet to freely spread and make free use of academic information and scientific research achievements. It is a brand-new publishing mode based on digital network environment; It is a brand-new academic information exchange and enjoyment mode based on the concept of "freedom, openness, * * construction and * * enjoyment"; It breaks the monopoly of academic journals, solves the problem that researchers can't get and use academic journals anytime and anywhere, and brings a brand-new concept and mode of literature resources construction and service to the library community.

Second, the types of OA resources

At present, there are four types of open access resources: open access journals, open access knowledge bases, electronic publications and open access search engines.