Readability vs. Legibility

Readability is how easy it is to read a lot of text or pages with extensive text. Legibility is how easy it is for the reader to recognize short burst of text. To make something legible  you don't want all the text to be the same size, i.e. all CAPS. When designing for web, it will be important to use a font that is easy to read and allows the eye to flow naturally over the text. The eyes recognize shapes of different words and when text is in all caps the eye takes longer to recognize and longer to read the text on screen and the more difficult to understand what is being seen. Designing for print is much different than designing for web, you want people to keep returning to your site and if it is not easy to navigate and easy to read and flow naturally with the eyes people will lose patience and leave your site.