This document summarizes key concepts around open access to research literature. It defines open access as research that is freely available online without financial or legal barriers, allowing anyone to read and reuse the work. Open access advocates that research should be openly shared to benefit science and society, rather than for financial gain. Creative Commons licenses are discussed as a way for authors to retain copyright while allowing certain uses of their work, such as non-commercial sharing and reuse. Overall the document promotes open sharing of research as beneficial to knowledge advancement.