Open Access Publishing Models

Open access (OA) publishing removes subscription paywalls, making research freely available to all readers online without subscription fees. The Budapest Open Access Initiative (2002) defined OA as the right to read, download, copy, distribute, print, search, and link research freely. Multiple OA models exist: Gold OA (immediate free access, often author-funded via APCs), Green OA (free self-archiving in repositories), and Diamond OA (free to both authors and readers). OA expands research impact, enables global participation in science, and aligns with public funding mandates. However, OA models vary in sustainability and are sometimes exploited by predatory publishers.