JavaBeans are reusable software components for Java that 
can be manipulated visually in a builder tool.[1] 
Practically, they are classes written in the Java 
programming language conforming to a particular convention. 
They are used to encapsulate many objects into a single 
object (the bean), so that the bean can be passed around 
rather than the individual objects.

Java bean is simply a java class which has getter and 
setter methods.
setter methods are used  to set the data.
getter methods are used to to get the data.

Java beans are used to encapsulate objects in a single java 
bean so that the bean can be used or passed in other 
classes. 

Like in our jsp we can use this bean by using <%jspusebean> 
tag.