Open Access is a method of disseminating and providing access to scientific publications via the internet. In principle, however, it encompasses all research outputs. The fundamental principles of Open Access are free accessibility and reusability. With Open Access, anyone can freely access research publications on the internet without financial, legal, or technical barriers. Differences in financial resources no longer affect access to knowledge. Moreover, appropriate licensing permits free redistribution or adaptation, provided authorship is correctly acknowledged. Compared with the traditional distribution channels of scientific publishers, Open Access offers considerably greater opportunities for both authors and readers.

There are several strategies for publishing in Open Access. The best known are the "gold route" and the "green route". In the gold route, a publication is immediately available in Open Access upon first publication. In the green route, access is provided through a secondary publication, while the original publication usually remains within the traditional subscription-based system. The (preferred) gold route, by contrast, is based on a different business model:

• Publication costs are no longer retrospectively recovered through purchase or licensing (usually by libraries), but are covered in advance by the producer. This primarily occurs through authors’ fees, but may also involve publisher financing, cooperative crowdfunding, or membership models.
• Any authors’ fees that are required are usually not paid by the authors themselves, but from project or institutional funds.
• In contrast to the traditional usage model, authors retain the rights to use their work. They therefore maintain control over it.