Any application that can be accessed using a web browser. The application can be as simple as a message board or guest sign-in page on a website, or as complex as a spreadsheet.
White space
The blank (not necessarily white) area between screen components such as text and images. White space is an important design element.
WiFi
Wireless fidelity. It is similar to Bluetooth in that it is used to exchange data, but the signals can travel further distances.
Wiki
A type of website that encourages collaboration by allowing users to add, edit and remove content.
Wizard
Part of a program that helps the user to create a new document, chart, etc. A sequence of dialogue boxes guides the user through the steps needed to create the item required.