Open access consists of providing on-line access to all available scientific information (articles, monographs, research data) free of charge for the reader and under licences that allow its use and exploitation by end users, without economic, legal or technological barriers.
It advocates the elimination of barriers that prevent access to the results of scientific research, mostly financed with public funds, and constitutes an alternative to the most widespread system of access to research results in the world, based on the payment of high fees or subscriptions to scientific journals paid for by universities and research centres.
It does not interfere with decisions to commercially exploit research results (e.g. patents), because the obligation to deposit in open access only occurs once the decision to publish has been made.
It does not mean that the publications are of lower quality, since they are subjected to the same peer review process as the commercial access publications.