This document discusses two-tier and three-tier architectures. In a two-tier architecture, clients communicate directly with servers, while a three-tier architecture introduces a middleware layer between clients and servers. Some benefits of three-tier include improved security, scalability, and the ability to use multiple databases. However, three-tier architectures also have higher costs and complexity compared to two-tier.

3. The client is a man who send the
request to the server .
Exp.
server
client

4. Who response of the request ,which
is send by client .
server
client

6. • There are two type
Two tier
Three tier

7. • The two-tier architecture is based on Client
Server architecture. The two-tier architecture
is like client server application. The direct
communication takes place between client
and server. There is no intermediate between
client and server.
• In a Two-Tier Architecture the applications
are mostly divided into a user-services tier
and a data-services tier.

8. • Tier 2: server platform, hosting all server
software components
Physical Architecture
GUI
Database
Server
Windows
Client
PowerBuilder
Visual Basic
Visual C++
Access
Paradox
Oracle
Sybase
Informix
MS SQLServer
Technical Architecture
…
Ethernet
Token Ring
TCP/IP

9. 1. Non-Complex
2. Non-time Critical information processing
system
3. User Interface in User side, database
management in the server side.
4. Easy to maintain and modification is bit easy.
5. Communication is faster

10. 1. Performance decrease if more than 100
users are involved
2. Interoperability is limited
3. System Administration is difficult

11. Presentation
Application
logic
Shared
data
Local-area network
Note: many clients per
application server, several
application servers per data server

12. • Three tier Architecture the business services are
assigned a separate tier – called middle tier and is
handled by middleware like MTS and IIS

13.  It overcomes all the disadvantages of Two Tier
Architecture, by providing a middle layer
 Improved Security – Client is not direct access to
database.
 three tier architecture application performance is
good.

14. 1. The development environment is more
difficult to use, than the Two Tier
development environment
2. The cost involved is much more than the
Two tier Architecture
3. Increase Complexity/Effort

15. Difference between 2-tier&3-tier
• Less secured as client can
talk to database directly.
• Complex as business logic
and database exist on one
system
• Only database should be
used
• Simple as layers are
separated
• Application server may
use services like RMI or
JMS etc.
• Multiple databases can be
used even within the same
transaction