There is a current global movement towards open digital reusable educational resources. Most reports on open educational resources (OER) and open educational practice (OEP) start by clarifying their understanding and definition of the terminology. In particular they offer their interpretation of the meaning of ‘open’ as used in the expression ‘open educational resource’ and in other expressions especially ‘open content’ and ‘open access’. Now ten years old, the historic definition of OER is essentially functional to allow legal safety to anyone reusing OER without paying royalties and without having to apply to the copyright owner for permission to reproduce the resource. The historical functional definition of OER was given by UNESCO (2002, p.1) as “technology-enabled, open provision of educational resources for consultation, use and adaptation by a community of users for non-commercial pur poses … typically made freely available over the Web or the Internet”. In simple words, the term open educational resource (OER) is used here to mean a small self-contained unit of self-assessable teaching with a measurable learning objective, often in digital electronic format and generally free to use.