Open-access (OA) literature is digital, online, free of charge, and free of most copyright and licensing restrictions. What makes it possible is the Internet and the consent of the author or copyright-holder.
OA literature is not free to produce, even if it is less expensive to produce then conventionally published literature. The question is not whether scholarly literature can be made costless, but whether there are better ways to pay the bills than by charging readers and creating access barriers. Business models for paying the bills depend on how OA is delivered.
Attribution: Extracted from A Very Brief Introduction to Open Access by Peter Suber, which is licensed under a Creative Commons Attribution 3.0 United States License.
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Open Access removes price barriers (subscriptions, licensing fees, pay-per-view fees) and permission barriers (most copyright and licensing restrictions).
Making your research Open Access
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