Accessibility starts with design. Most designs for web sites make certain assumptions about the people who will visit the site.

For example, most designers assume that a user will have a standard keyboard and mouse to navigate the web. This means that designers assume visitors can click on links easily and move around the page. This also assumes that visitors can see the page as designed.

People with alternative hardware may not have the ability to click on links or navigate a page. People with disabilities may not be able to use a mouse or may not be able to see the screen. A user with low vision may use a screen reader to navigate the web. A user may use buttons to navigate the web instead of a mouse.

As a web designer, I know it is vital to test the design with various tools of accessibility, such as screen readers, in order to understand the user's experience of the web.