Struts uses ActionForms to transfer the request parameters from the client to the execute() in the Action class on the server. It abstracts the usage of the HttpRequest.getParameter() which had to be used to retrieve each individual parameter till the Struts came along. The request parameters could then be processed as appropriate.
The reuse part means that Struts does not create new instances of the Form bean mapped to a particular form. If one is available it is used after calling the reset() method the nest time the same form is submitted.
Cheers, Raj. [ July 10, 2008: Message edited by: Raj Kamal ]
Obviously the ActionForm is nothing but the carrier for the having the values set in the HTML form and which is what getting bound to the appropriate properties of the Form Bean you have. Instead of recreating new ActionForms, it is better reused!