We are now faced with numerous examples of the use of the word ‘open’ in the context of education. There are open schools, open universities, open participatory learning infrastructures (OPLI), open courseware (OCW), massive open online courses (MOOCs), open educational resources (OER), open educational practices (OEP) and so on (see, e.g., Atkins, Brown, & Hammond, 2007; Schuwer, van Genuchten, & Hatton, 2015). What these terms at face value seem to share is their reference to the removal of barriers to the access of education. Open universities have relaxed entrance requirements, open courseware and MOOCs allow for free access to courses, as do open educational resources and open educational practices at the levels of materials and practices, respectively, although the kinds of barriers removed and the extent to which they are removed differ widely (Mulder & Jansen, 2015). However, there is more to openness than this prima facie characterization in terms of the removal of barriers reveals. A brief overview of some existing definitions of openness in education can help to make this evident.