Basically, it's all about components. Let's say you have a Windows
application that performs a set of tasks. Now your boss tells you that it
needs to run as a Web Service. If the UI (presentation) logic is mixed up
with the business (task) logic, this is going to be a bear to do. You'll
have to slog through all that code and filter out the business code from the
presentation code. But if you put these into separate components (tiers),
you can easily plug your business code into any type of user interface or
API.
There's more to it, of course, but that's the basic principle. Software
evolves. Build it for evolution, extensibility, scalability.
See the links that Bjorn supplied for more detailed information. But never
forget the basic principles.
--
HTH,
Kevin Spencer
Microsoft MVP
..Net Developer
There's a seeker born every minute.
- Dr. "Happy" Harry Cox
"RAJESH" <RA****@discussions.microsoft.com> wrote in message
news:12**********************************@microsof t.com...
I am working with c# and asp.net in developing web applications, iam using
.netframework 1.1 ,i want to know what is the need of 3-tier or 4-tier
architecture in our application development.what is its part when some
body
is using our application.plese give links where i can find the answer.