Why empty tag is required in Java Struts?
When the requested variable does not contain any information, (null or empty) then this tag is used to know the contents present in the other body parts of the tag. If the tag is nested then it is advisable to use this tag as it may contain a bit of information.
How the struts dispatch action works?
Org.apache.struts.actions.Dispatchaction interface gives the user to collect all the information and functions into a single action file. This interface is very useful because it helps you in developing a common action for all the functions.
Explain tags in context of Struts
The tag is present in the HTML library provided by Struts. This tag informs the browser to pretend that the original tag is located at somewhere other than the current url. This tag is responsible in creating a base tag which gives a false impression to the user via browser about the exact location of the url.