Open educational resources (OER) refer to teaching and learning materials that are freely available for public use, with few or no restrictions from copyright. OER may include full courses, textbooks, videos, tests or any other education materials. Key advantages of OER include lower costs for students, adaptability of the materials, and allowing instructors to focus on teaching rather than developing new content. However, finding and editing suitable OER can require significant time and effort from instructors. When using OER, it is important to verify the copyright license and ensure materials are properly attributed.