Open licensing refers to licenses which grant permission to others to access, re-use and redistribute a work with few or no restrictions.
Open Educational Resources (OER) refers to teaching and learning materials released under an open licence.
Creative Commons is an international non-profit organisation that provides free licences and tools that copyright owners can use to allow others to share, reuse and remix their material, legally. The six standardised CC licences each allow material to be used in a different way.
Open access (OA) publishing is typically used to refer to research publications released under an open licence. Scholarly research published under an open licence is typically found in Open Access journals and in institutional repositories such as the University of South Australia Research Outputs Repository.