Designed to be flexible, JavaServer Faces(JSF) technology leverages existing, standard UI and web-tier concepts without any restrictions to a
particular mark-up language, protocol, or client device. The UI component classes included with JavaServer Faces technology encapsulate the component functionality, not the client-specific presentation, thus enabling JavaServer Faces UI components to be rendered to various client devices. By combining the UI component functionality with custom renderers, which define rendering attributes for a specific UI component, one can construct custom tags to a particular client device.

Ease-of-use being the primary goal, the JavaServer Faces architecture clearly defines a separation between application logic and presentation while making it easy to connect the presentation layer to the application code. This design enables each member of a web application development team to focus on his or her piece of the development process, and it also provides a simple programming model to link the pieces together. For example, web page developers with no programming expertise can use JavaServer Faces UI component tags to link to application code from within a web page without writing any scripts.