Java Web Start is a deployment technology for Java based applications. It is the plumbing between the computer and the Internet that allows the user to launch and manage applications right off the Web. Java Web Start provides easy, one-click activation of applications, and guarantees that you are always running the latest version, eliminating complicated installation or upgrade procedures. Java Web Start technology provides the same benefits to full-featured applications as HTML-based applications. Its an application deployment solution for the Web, Using a full-featured application instead of an HTML-based client so have many benefits:

A highly-interactive user interface, comparable to traditional applications, such as word processors and spreadsheets.

The user interface is very rich and responsive Lower bandwidth requirements. An application does not necessarily have to connect back to the Web server on each click, and it can cache already-downloaded information. Thus, it can provide better interactivity on slow connections.

Support for off-line use. Applications are easy to launch from Start Menu, Desktop, or by other means - and do not necessarily require the Web browser to be running The speed and responsiveness of the application does not depend on the connection speed Traditional applications also have a number of problems. In particular, applications are often complicated to install, and even worse to upgrade. Keeping software up-to-date is typically a major headache.

The trade-off is that you have to download the application the first time. A Java TM technology-based application will require download times in the order of minutes on a typical modem connection. Java Web Start caches all downloaded files locally on the computer. Thus, although the first-time activation cost is higher for applications than for HTML pages, the subsequent times you launch an application, it will be launched almost instantaneously, since all the required resources are already available locally.