JavaServer Faces (JSF) is a user interface (UI) framework for Java web applications. It

is designed to significantly ease the burden of writing and maintaining applications

that run on a Java application server and render their UIs back to a target client. JSF

provides ease-of-use in the following ways:

• Makes it easy to construct a UI from a set of reusable UI components

• Simplifies migration of application data to and from the UI

• Helps manage UI state across server requests

• Provides a simple model for wiring client-generated events to server-side application code

• Allows custom UI components to be easily built and re-used

Most importantly, JSF establishes standards which are designed to be leveraged by

tools to provide a developer experience which is accessible to a wide variety of

developer types, ranging from corporate developers to systems programmers. A

"corporate developer" is characterized as an individual who is proficient in writing

procedural code and business logic, but is not necessarily skilled in object-oriented

programming. A "systems programmer" understands object-oriented fundamentals,

including abstraction and designing for re-use. A corporate developer typically

relies on tools for development, while a system programmer may define his or her

tool as a text editor for writing code.

Therefore, JSF is designed to be tooled, but also exposes the framework and

programming model as APIs so that it can be used outside of tools, as is sometimes

required by systems programmers.

(Quote from the JavaServer Faces Specification)