As open source software and open educational resources (OER) communities have grown and their products have begun to compete with and complement commercial products, open resources have become more widely used in both K-12 and higher education. Baker (2017) suggested open resources are defined by dimensions of transparency and freedom, and these characteristics can be traced through the information products created by educators for many generations. Transparency is that characteristic of open resources that allows users to access and modify the original works; freedom is that characteristic that allows use of the products without the need to purchase or license the work. More importantly, however, freedom entails the rights to create and distribute derivative works.
Baker, F. W. (2017). An alternative approach: Openness in education over the last 100 years. TechTrends, 61(2), 130–140.