This chapter provides an over of an exciting technology that is at the forefront of Java programming Java Beans. Beans are Important, because they allow you to build complex systems from software components. These components may be provided by you or supplied by one or more different vendors. Java Beans defines an architecture that specifies how these building blocks can operate together. To better understand the value of Beans, consider the following. Hardware designers have a wide variety of components that can be integrated together to construct a system. Resistors, capacitors, and conductors are examples· of simple building blocks. Integrated . circuits provide more advanced functionality. All of these different parts can be reused. It is not necessary or possible to rebuild these capabilities each time a new system is needed. Also, the same .pieces can be used in different types of circuits. This i s possible because the behavior of these components is understood and documented. Unfortunately, the software industry has not been as successful in achieving the benefits of re usability and interchangeability. Large applications grow in complexity and become very difficult to maintain and enhance. Part of the problem is that, until recently, there has not been a standard, portable way to write a software’ component. To achieve the benefits of component software, a component architecture is needed that allows programs to be assembled from software building blocks, perhaps provided by different vendors. It must also be possible for a designer to select a component, understand its’ capabilities, and incorporate it into an application. When a new version of a component becomes available, it should be easy to incorporate this functionality into existing code. Fortunately, Java Beans provides just such an architecture. . This chapter begins by defining a Java Bean and describing the advantages it . provides for a software designer. You will see howto use the Beans Developer Kit . (BDK) that from Java This a tool that allows you to interconnect . several Beans. Finally, you will see the step-by-step process required to write a simple Bean and use it in the BDK.