This document discusses open educational resources (OER) which are teaching, learning, and research materials in any format that reside in the public domain or are released under an open license allowing free access, use, adaptation, and redistribution. OER come in diverse formats including images, videos, textbooks, and tests. They are defined by UNESCO as materials that can be reused, redistributed, revised, and remixed freely as long as the author is attributed. The document outlines advantages like contributing to global education and allowing collaboration, and disadvantages such as requiring internet access and potential lack of accuracy or knowledge about available resources.