"Open educational resources (OER) are any resources available at little or no cost that can be used for teaching, learning, or research. The term can include textbooks, course readings, and other learning content; simulations, games, and other learning applications; syllabi, quizzes, and assessment tools; and virtually any other material that can be used for educational purposes."
The above video summarizes a research article that synthesizes the results of 16 studies examinig the effectiveness of OER. (Hilton, John. "Open educational resources and college textbook choices: A review of research on efficacy and perceptions." Educational technology research and development 64 (2016): 573-590.)
Open Educational Resources (OER) can:
Provide instructors flexibility by their ability to be customized to meet the specific needs of a course.
Provide a wider audience for authors/creators
Expand the reach of authors/creators to a wider audience.
Empower under-represented communities by eliminating obstacles to publishing and sharing their work