Open Access (OA) publications consists of journal articles and books that are online, free of charge, and free of most copyright and licensing restrictions related to reuse. Online journals and books that are open access have no subscription cost or pay-per-use fees. Some benefits to OA include
Summarized from UNESCO Open Access Publications
Additionally:
Open Access Explained by Piled Higher and Deeper (PHD Comics) on YouTube.
The open access movement aims to transform the traditional scholarly publication model to one that is more equitable and beneficial to society. Existing models have created an ecosystem where journal publishers charge exorbitant subscription fees, typically paid by libraries, for access to research which may often be publicly funded. This not only creates a funding crisis for libraries, but it delays access to research for the public and only allows access to the privileged few who can afford to pay article charges. The open access model aims to eliminate barriers to research access by providing a number of ways for researchers to share their work more openly. This is an evolving model that has varying degrees of adoption across different fields.
Influential documents on the open access movement:
Further resources and readings on the advantages of open access publishing