This is possible by<jsp:forward  page="/xyz.jsp"/>
forward is nothing but it will goes directly to next jsp page.
It will no look after the current JSP page

Use Tiles framework or Ajax technology to refresh a part of 
the page. We could also use portlets for the same.

You need to change the port number from server.xml

Yes it running multiple tomcat server in single machine.you
need chang the port number at the time instalation of tomcat
server or other change port number in server.xml file in
Tomcat located in your system

Note: Better  to use default port numbers grater than 1000
beacuse less than 1000 are predefined for Operatin system or
others

The Java Filter gives effective protection against unwanted
execution of Java applets, without having to switch off Java
support of your browser. For example, you could only allow
applets from within your firewall onto your computer.

choose 
 Tools-internet options-Browsing history

press delete-it opens one window with several option 
choose  Delete cookies.cookies get deleted.

Some cookies have an expiration set, in this case the cookie
is deleted after the time expires. The cookies without an
expiration time are deleted after the session ends.

you just set the maxAge ofcookie as 0


as 
myCookie.setMaxAge(0);

when browser will close the cokie will also be closed.

otherwise set the age of cookie -1 for istant deleting of
cookie.

jndi expanson is(java naming and directory interface)its is 
an api(applivation programing interface)which helps to 
access the directory and naming services

java naming directory interface

With respect to a computer filesystem, an access control 
list (ACL) is a list of permissions attached to an object. 
The list specifies who or what is allowed to access the 
object and what operations are allowed to be performed on 
the object. In a typical ACL, each entry in the list 
specifies a subject and an operation: for example, the 
entry (Alice, delete) on the ACL for file WXY gives Alice 
permission to delete file WXY.

webserver  :
1)webserver imlementation on servlet,jsp Api specifation.
2)less middleware services
3)its recoginses only WAR files
4}its understand only http requset
5}its develop only webapplications.
Ex: tomcat server
Applicationserver:
1)Application server implementation on All J2EE specifications
2)more middle ware services( nearly 16 middle ware)
 Ex:connection pooling,security,transaction management
3)its recoginses  WAR,RAR,EAR files
4)its understand http,non http requsets
5}its develop  webapplications and enterpraise
applications,distributed applications.
ex:-weblogic

FORMULA:
APPLICTION SERVER=WEBSERVER+MIDDLEWARE SERVERICE+EJB CONTAINER

The archtechture followed in developing any web application 
is MVC ( Model View Controller ).The Model part is the Java 
bean(Value objects) used in the application,the View may be 
HTML,Jsp etc and the controller part is the servlet where 
the actual business logic is implemented.

THE web application follwed by MVC architectute

MODEL----->Persistance logic+Middle ware services(JDBC with
coonection pooling)

View------->presentation layer(html,jsp)

Controller------->controll the all the component +
integration logic(connect with DAO)

Web architecture, the focus is properly on the user and on user requirements. This requires particular attention to web content, a business plan, usability, interaction design, information architecture and web design.

Web architecture entirely depends J2EE standards and folder structure. It depends on the design patterns we define as per the user requirements...Ex: MVC architecture.