Accessibility means that web sites are created to ensure that those with disabilities are able to access the pages.
For example, in order to ensure that a person with a visual impairment is able to understand a page with images, all images should have "alt" (alternative representation) tags when they are inserted into a document. These tags can easily be added in when an HTML editor is used to create web pages.
To view an alt tag, hold your mouse over the image at the top of this page. A little text message that describes the image will appear . This is to ensure that a screen reader (used to interpret web page information by a person with a visual impairment) will describe the image.
Much has been written about both accessibility and usability with web pages.
George Brown College is the first college in Ontario to have developed a policy on web page accessibility.
It can be viewed on the college intranet.
Usability means that web sites are constructed in such a way that users can easily find information, navigate throughout the site etc.
Dig Deeper
Would you like more information on ensuring that your web pages are accessible?
Take this introductory tutorial on Web Accessibility.
You may also want to visit this EASI (Equal Access to Software and Information) site that provides workshops and web conferences on improving accessibility in the online environment.