Open access (OA) is a publishing model that provides an alternative to the traditional scholarly publishing model. There are different ways that open access can manifest, but for an initiative to be considered open access it must be free of price barriers such as paywalls, subscription costs to end users, or other charges/fees to access materials. OA resources must also be free of most kinds of permission barriers, such as copyright and licensing restrictions around (re)distribution of the materials. OA permissions may grant the user the right to copy, use, change, distribute or display the information, as long as the original author is given credit. OA does not change how information is created; rather, it changes how it is distributed. In a nutshell, Open Access attempts to make digital information freely available and easy to share.
For an excellent introduction to Open Access see Peter Suber's Open Access Overview. For an introduction to Open Access and libraries, the Association of Research Libraries offers a great overview of key issues.
There are a variety of benefits and challenges to the open access publishing model.
Open access is about distribution and making information available; it does not significantly change the production of research, and does not seek to change author rights. In fact, in most cases authors who publish via an open access model retain more rights over their their works that when publishing under a traditional model. Authors who publish via open access agree to right of use, allowing unrestricted distribution (reading, downloading, copying, sharing, storing, and printing) of the full-text work, so long as the original author is given credit. Authors may choose to license their works under open content licensing, such as Creative Commons.
To search for permissions given by publishers as part of a journal publisher's copyright transfer agreement see the SHERPA/RoMEo tool.
Intellectual property includes patents, copyright, trade-marks and industrial design. These rights protect intangible subjects that are produced as a result of human creativity. Intellectual property rights mean that other people can be stopped from using the "property" and that the rights can be transferred. Open access does not change intellectual property rights. For information about intellectual property in Canada see the Canadian Intellectual Property Office.
Most journals that use an open access model ensure that works are published under the current copyright system or using a Creative Commons license. Authors typically remain as copyright holders, but allow for the general public to freely use and redistribute their work, giving credit to the author. Authors can agree to have their work publicly accessed or publicly accessed and modified. The Canadian Copyright Act is available online.