As used in servlets and JSP, a JavaBean is just a Java class that follows certain naming and access conventions which let you take shortcuts in JSP page code. If you don't want to use those shortcuts, don't use bean conventions. In any helper class - bean or non-bean - you just need to keep in mind the scope of the object as related to the multi-threaded nature of web applications. Bill
Beans are used especially when you want to hold some data and this data can be transmitted from business layer to presentation or database layer to business layer etc. Most cases to hold data use bean. At the same time beans are some type of Java classes with some convention rule such as it should have a constructor with zero arguments, data member and setter, getter methods. When you come accross to use a java class it can be use for any activities apart from holding data.
Java beans are very important with respect to JSP since many of the JSP mechanisms, be they JSP actions that operate upon data or the new Expression Language (EL), expect data to be bean-patterned. Non-bean-patterned data just won't work well with these mechanisms.