Open education practices is the umbrella term for teaching and learning activities that included creation, use, and reuse of open education resources such as open textbooks, open pedagogies and the sharing of teaching practices. Open textbooks are textbooks that have been funded, published, and licensed to be freely used, adapted, and distributed. Open Educational Resources (OER) are teaching, learning and research materials in any medium that reside in the public domain or have been released under an open license that permits no-cost access, use, adaptation and redistribution by others. Open Education is part of a broader ecosystem of open (Open Education, yes, but also Open Access, Open Science, Open Data, Open Source, Open Government).
