Since Oliver's guide was first published in 2010, thousands of LIS students, records managers, and catalogers and other library professionals have relied on its clear, plainspoken explanation of RDA: Resource Description and Access as their first step towards becoming acquainted with the cataloging standard. Now, reflecting the changes to RDA after the completion of the 3R Project, Oliver brings her Special Report up to date. This essential primer concisely explains what RDA is, its basic features, and the main factors in its development; describes RDA's relationship to the international standards and models that continue to influence its evolution; provides an overview of the latest developments, focusing on the impact of the 3R Project, the results of aligning RDA with IFLA's Library Reference Model (LRM), and the outcomes of internationalization; illustrates how information is organized in the post 3R Toolkit and explains how to navigate through this new structure; and discusses how RDA continues to enable improved resource discovery both in traditional and new applications, including the linked data environment. The new edition of Introducing RDA will prove just as indispensable as the first for novices and seasoned veterans alike.