Definition:
Wireframes are an important design tool used in Web development. It is a visualization tool for presenting proposed functions, structure and content of a Web page or Web site. A wireframe separates the graphic elements of a Web site from the functional elements in such a way that Web teams can easily explain how users will interact with the Web site. A typical wireframe includes:
(1) key page elements and their location, such as header, footer, navigation, content objects, branding elements, (2) grouping of elements, such as side bars, navigation bars, content areas, (3) labeling, page title, navigation links, headings to content objects, and (4) place holders, content text and images.
User Experience Dictionary
Definition:
Web applications are stored on a server and delivered to users over the Internet. A Web application is usually a three-tier structure, comprising a User Service tier (allowing user access to the application), a Business Service tier (allowing the user to carry out complex activities) and a Data Service tier (which allows data storage and retrieval).
User Experience Dictionary