Uniform Resource Locator (URL)

   The address of a homepage on the WWW.

Universal Design

   Universal design is the design of products and environments to be usable by all people, to the greatest extent possible, without the need for adaptation or specialized design.

Uplink

   The earth station used to transmit signals to a satellite.

Usability

   Usability relates to the ease of use of a product such as a Web site. The International Standards Organization (ISO) officially defines "usability" as "The effectiveness, efficiency and satisfaction with which a specified set of users can achieve a specified set of tasks in a particular environment". Usability is essentially a measure of a product's potential to accomplish the goals of the user. Usability is affected by a number of factors such as navigation, visual consistency, clearly defined processes, interface design, information architecture, etc.