Beyond reading without a paywall
The Budapest declaration of 14 February 2002 framed open access around scholarly literature available on the public internet, including reuse beyond reading, such as copying, searching and indexing.
Temporary free viewing alone does not specify a lasting permission. Readers need to identify the accessible version, applicable terms and provenance, including differences between an author-held manuscript and the published version.
Repositories and journals
Self-archiving deposits eligible articles in electronic repositories; open-access journals provide access through publication. These routes can coexist without being the same workflow.
UNESCO also emphasizes preservation, interoperability and linking publications with research outputs such as data and software. Continued availability depends on infrastructure, not merely placing a file on one webpage.
Funding and quality are separate questions
Removing reader charges does not eliminate editing, preservation and dissemination costs. Budapest listed several funding possibilities rather than prescribing author charges as the only model.
Open availability does not itself establish peer review. The declaration includes voluntarily shared preprints, while UNESCO calls for distinguishing them from final peer-reviewed publications. Research quality still requires examination of methods, versions and actual evaluation.