Conversation on system architecture

A telephonic conversation between my friend and me regarding system architecture

Sangita: Hello! How are you?

Me: Hi! I am fine dear. How is your new MBA College?

Sangita: I am loving it. Just taking some time to get adjusted with the new schedule.

Me: Yes don’t worry you will soon be able to cope up.

Sangita: Yes. I need a help from you. Since you are good at IT it will be of great help if you can explain me system architecture. I am having difficulty in understanding that part.

Me: yes surely. A system architecture is the conceptual model that defines the structure, behavior, and more views of a system. It is basically description and representation of a system, organized in a way that supports reasoning about the structure of the system which comprises system components, the externally visible properties of those components, the relationships between them, and provides a plan from which products can be procured, and systems developed, that will work together to implement the overall system.

Sangita: Ok does it simply mean the interconnection between hardware and software components in a network?

Me: yes exactly.

Sangita: and what are the different kinds of system architecture?

Me:  We have different kinds of System Architecture as Single tier integrated Systems, Two-tier: client server architecture, Three-tier architecture and Multi-tier architecture.

Sangita: Can you please explain each?

Me: Yes. Starting with single tier integrated systems, in this, data and application can be on the same physical hardware like laptop, desktop but data must be logically distinct from application. 

Sangita: ok. And what about two tier?

Me: In two tier: client server architecture, the data is stored with the server, and the applications are stored with clients, who have individual machines. The server and the clients are interconnected by Local Area Network (LAN).

Sangita: yes I got it.

Me: another thing I would like to add is the software used by the server are oracle, MySQL, SQL Server, DB2, etc.

Sangita: Ok and what are the applications used?

Me: the applications contain both the business rules (business logic) and the GUI (Graphical User Interface) which is the presentation logic.

Sangita: What are the advantages and disadvantages of two-tier?

Me: The advantages include it does not place processing burden on server machine when you have hundreds of users. To tell about its disadvantages firstly it requires high bandwidth which slows down the application. Secondly, we have to do maintenance of distributed software.

Sangita: What is three-tier architecture?

Me: In three-tier architecture application is partitioned where the business logic is kept centrally and the presentation logic is kept on the client.

Sangita: Ok and what about multi-tier architecture?

Me: multi-tier architecture is a client–server architecture in which the presentation, the application processing, and the data management are logically separate processes.

Sangita: How does the client access the data?

Me: The client access through Wide Area Network (WAN).

Sangita: What are its advantages and disadvantages?

Me: Advantage is there is no need for specialist software at each client location. Disadvantage is that business application has to be web enabled.

Sangita: Ok I think I got a good idea on system architecture. We can discuss more later.

Me: yes absolutely. Call me if you have any problem.

Sangita: Thank you so much.

Me: You are welcome. But I understood so well because of our faculty of Business information systems at Praxis, Prof. Prithwis Mukherjee.

Sangita: Nice to know that. I will call you up further for any help. Good night.

Me: Anytime. Good night.