Open Educational Resources (OER) are teaching and learning materials that reside in the public domain or are released with an open license that allows for free use, adaptation, and distribution. OER can include textbooks, videos, tests, software, and other materials used to support education. They are different from open learning in that OER focus primarily on content while open learning includes content and services. Major OER initiatives include SkillsCommons, OpenStax CNX, OER Africa, WikiEducator, and OpenCourseWare which provide open educational content and resources that can be reused and adapted for teaching and learning.