The model is the internal state of the application. This state is composed of both the data model and the business logic. From the high-level black box view, the data and the business logic merge together into the monolithic state of the application. For instance, if you are logging in to an application, both business logic and data from the database will be involved in the authentication process. Most likely, the business logic will provide an authentication method that will take the username and password and verify them against some persisted data from the database.

 
Actions do three things. 
Actions Encapsulate The Unit of Work:- The action fulfills the role of the MVC model for the framework. responsibilities of this role is business logic; actions use the execute() method for this purpose. The code inside this method should concern itself only with the logic of the work associated with the request.
 Actions Provide Locus For Data Transfer:- Being the model component of the framework also means that the action is expected to carry the data around.Since the data is held local to the action, it’s always conveniently available during the execution of the business logic. There might be a bunch of JavaBeans properties adding lines of code to the action, but when the execute() method references the data in those properties, the proximity of the data makes that code all the more succinct.
 Actions Return Control String For Result Routong:- The final duty of an action component is to return a control string that selects the result that should be rendered. 
Actions Encapsulate The Unit of Work:-

public String execute() {
setCustomGreeting( GREETING + getName() );
return "SUCCESS";
}

Actions Provide Locus For Data Transfer:-

private String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
private String customGreeting;
public String getCustomGreeting()
{
return customGreeting;
}
public void setCustomGreeting( String customGreeting ){
this.customGreeting = customGreeting;
}

Actions Return Control String For Result Routong:-

<action name="HelloWorld" class="manning.chapterOne.HelloWorld">
<result name="SUCCESS">/chapterTwo/HelloWorld.jsp</result>
<result name="ERROR">/chapterTwo/Error.jsp</result>
</action>




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