Accessibility in short is the process of making websites and website content percievable and usable by people with disabilities.
With Georgia Tech receiving federal funding, all colleges, schools, research centers and other departments and divisions of the institute are legally required to adhere to the official accessibility standards defined in Section 508 of the Workforce Rehabilitaion Act. These standards define how information is to be presented in websites and other online materials so that users with disabilities can still properly access that information.
As a good starting point for anyone creating web content, the Ivan Allen College has provided a short fifteen minute Accessibility Primer that addresses the most common problems and how to prevent or correct them. It covers accessibility issues with images, headings, lists, page layouts, navigational aides, and handling audio and video content. In addition, the WebAIM organization provides simple explanations of the general principles of accessibility.
OIT now has an Accesibility Resources page covering a wider range of IT accessibility beyond just web pages and web applications.