A JavaBean is a Java class that encapsulates many objects into a single object. It is a reusable software component that should follow certain conventions. These conventions include:

• Implementing the Serializable interface.
• Having a public no-arg constructor.
• All properties in the JavaBean must be private with public getters and setter methods.
• The setter method should be public, return void, and prefixed with "set".
• The getter method should be public and prefixed with "get".

JavaBeans are used to make it easier to access and manage multiple objects from a single object. They are a key concept in the Spring Framework, where they form the backbone of an application and are managed by the Spring IoC container. The JavaBeans functionality is provided by a set of classes and interfaces in the java.beans package.