Rapid prototyping is the process of quickly generating mock-ups of what a website will look like.
Readability
Readability is the degree to which the meaning of text is understandable, based on the complexity of sentences and the difficulty of vocabulary. Indexes for readability usually rank usability by the age or grade level required for someone to be able to readily understand a reading passage.
Relative Sizing
Relative sizing is scalable. It is the opposite of absolute sizing. For usability and accessibility it is better to use relative rather than absolute sized units. Use relative units such as percent or ems. Many low-vision users make use of devices to enlarge content displayed on their monitors. By using relative units, these users are able to change the size of the text without much difficulty.
Replaced Element
Elements those whose content is outside of the document. Examples of replaced elements are things like images and form elements.
RSS
RSS is a technology that notifies you when a web site is updated, and allows you to read the updates without visiting the site itself.
