Open Access
Open access refers to the distribution of research outputs (including pre-prints, data, and peer reviewed articles) freely online, subject to an open license. Open access can be achieved by publishing in an open access venue or archiving a version in an open access repository.
Open Data
Open data refers to data that are openly available and openly licensed. Open data are free to everyone to use and re-use as they want, without restrictions.
Open Education
Open education includes tools, practices, and resources that leverage knowledge sharing, technology, open licenses, and collaboration in service of learning. Open educational resources (OER) are freely and publicly available teaching, learning, and research resources (e.g. simulations, textbooks, or videos) that are free of copyright or openly licensed.
Open Licenses
Open licenses allow a copyright holder (usually the author) to grant permission to the public to make certain uses of their work, typically subject to certain conditions (such as providing attribution to the author). Creative Commons (CC) licenses are a suite of standardized open content licenses that authors (and other copyright owners) can use to enable their work to be copied, adapted, and shared. Creators of software can use open software licenses to grant the public permission to use, modify, and distribute software and source code.
Open Source
Open source refers to software that is free to use and reuse at no cost. Open source software is made openly available under a license, for example from opensource.org, that allows anyone to access, use, share, and modify it without needing to ask permission.
Publication Types
Check sherpa.ac.uk/romeo/ for concise definitions of publication types eligible for open access via publishers and repositories: