Open Access in general means research that is published on the web, free to all readers. It is an alternative to traditional publishing where readers pay a subscription fee to receive print (or online) publications. The idea behind open access is that with current technologies it is very easy to provide information freely on the web. This allows research to have more impact by reaching a larger audience.
From the Open Access Week web site:
“'Open Access' to information – the free, immediate, online access to the results of scholarly research, and the right to use and re-use those results as you need – has the power to transform the way research and scientific inquiry are conducted. It has direct and widespread implications for academia, medicine, science, industry, and for society as a whole.
Open Access (OA) has the potential to maximize research investments, increase the exposure and use of published research, facilitate the ability to conduct research across available literature, and enhance the overall advancement of scholarship. Research funding agencies, academic institutions, researchers and scientists, teachers, students, and members of the general public are supporting a move towards Open Access in increasing numbers every year."
Interested in publishing in Open Access journals? Check out these links for more information.