Me: Hi Siddhu :)
Siddhu: Hi bro. Whats going on in Kgp?
Me: Classes started and I am buried in assignments already
Siddhu: Ohh.... Explain me an assignment given to you
Me: Ok. Do you know anything about System Architecture?
Siddhu: Heard the term. But don't have an idea what it is.
Me: System Architecure is an architecture which tells us where different entities needed for an application and data reside and how do they coordinate
Siddhu: Ok. Are there different types of system architectures?
Me: Yes. The first one is Single tier architecture where the data and the application reside on the same machine.
Siddhu: Can you tell me some tools which use single tier architecture?
Me: Ya. All Microsoft Office tools like MS Word, MS Excel etc., come under this. When we install these tools in any personal computer, the application and the data both resides on the same machine. We can take the data file to an another system in which MS Office is installed and we can open that data file. These type of data files are application specific. We cannot see the data without the corresponding application installed on our computer.
Siddhu: Ok. Next type please!
Me: The next type is Two tier architecture where the application and data will be on two different machines
Siddhu: Hmm..... two different machines?
Me: Yes. Data will be there on a common shared dedicated system (server). And the applications are installed on individual user machines which will access the data server though TCP/IP protocols
Siddhu: What are the pros and cons?
Me: Advantage is that processing burden decreases on the individual machines. And the disadvantage is that when we upgrade the application to next version, we need to change that on every individual machine.
Siddhu: Ohh. Is any architecture got rid of this problem?
Me: Yes. The next type is Three level architecture where it didn't has this problem?
Siddhu: How is it structured?
Me: Data, business logic part of application and front end of application reside on three different machines. So that if we need to change any business logic of the application, we need not change in every individual machine. And the data transfer over the network is minimized. In this type, data transfer is through TCP/IP
Siddhu: Ok.
Me: Next is Multi tier architecture, where we use internet for the data transfer among servers and client machines. Apart from this change this is same as Three tier architecture
Siddhu: What is the difference between TCP/IP and internet?
Me: The basic difference is that TCP/IP is private network and internet is public.
Siddhu: If it is public, don't we need any security?
Me: Yes exactly. We need to secure our data using Firewall when using internet.
Siddhu: Ok. Next type please.
Me: Thats what I know. Probably those are the types we have. And I have to present these in assignment for tomorrow. Its already getting late and I have to finish that work. So leave me and go to bed. Bye and good night.
Siddhu: Bye Anna. Good night tc :) :)
