This document discusses open educational resources (OER). It defines OER as teaching, learning and research materials that reside in the public domain or have been released under an open license permitting free access, use, adaptation and redistribution with limited or no restrictions. The document outlines the history and development of OER, including early initiatives from MIT and UNESCO. It also discusses the role of open licensing in defining what makes educational resources open and how people can interact with open content through retaining, reusing, revising, remixing and redistributing it. Government, institution and teacher recommendations from the 2012 OER Paris Declaration are also summarized.