client server is a 2-tier application . 
it contains views and reports at the frontend in this it 
monitors and manipulates the data.
and the database server at the backned in this it stores 
and retrieves the data such as from oracle,ms access,ms sql

where as web application is a 3-tier application
browser: Monitors the data
Web server: Manipulates the data by using some programing 
languages like java,...
Database server:stores and retrieves the data from the 
database

In web Application,we will use any one of the webse5r and 
we will deploy all the web components into that server. 
Even client components also will be in server only. Once 
the user send the request through browser then only the 
appropriate component will download to user machine and it 
will execute in browser. eg : yahoo mail

but in clientserver application, the client application 
will be in client machine and one machine in remote place 
acts as a server. in that server pc one server application 
will run, whenever client requests then it will receive 
that and send the response to client. eg : yahoo messenger.


regds,
swathi,
swty79@rediffmail.com

Hi Friends,

I am also hunting for job like you guys. Thanks for the 
requests for clarification of web application as 2-tier.

for eg : lets us take an example of user logging into 
portal.

the webpage(where you are providing username and password) 
is a front end page and its clear we treat it as one tier. 
Once you enter username and password, these must be 
validated.  There are two options, you can validate in the 
same jsp page or you can use another servlet to validate 
these user credentials and delegate the request to 
appropriate page on success. 

Here the point is if you are validating the username and 
password in the same jsp which means the frontend page(lets 
think as a jsp) is directly interacting with 
database...then we can treat it as a two tier. Incase if 
this jsp is again talking to other servlet saying..."hey 
servlet...please validate this user id and password and 
decide yourselves what ever you want to do if success or 
failuer? " then simply this servlet will validate and 
forward to database if success  otherwise it will forward 
to error.jsp saying invalid username and password..so this 
can be treated as three tier.

Most of the time two tier is not recommended 
because..According to Jsp specification..jsp are good to 
use as presentation purpose but not for controlling and 
performing bussiness logic..This is what all I know


regds,
swati

few more points on client server application and web 
application.

Client- server applications: Application is loaded at the 
server. In every client machine, an exe is loaded to call 
this application. 

Web Based application : Application is loaded at the 
server.but,No exe is installed at the client machine. We 
have to call the application through browser. usually we 
use http protocols to communicate.

Following are the few differences in between Client server
and web application:

1)For launching the client server there is no need for web
server and data base server where as if we want to launch
the web application first we must start the web server along
with data base server.

2)In order to open client server application we must first
installed in a specific system then only we can able to
open,there is no need to install the web application simply
we can start it by giving a unique and specific url'

3)Client server application is menu driven application where
as web server is lick driven application

4)Client server consists of less content where as web server
application consists os more content when compared to client
server application