Knowledge Transfer to Friend

Sagar: Hi sarat, how are you?

Me: Hi Sagar, I am good. Wat about you? I am sorry I could not make it to the cricket match last week.

Sagar: I am good too. We missed your skill with the ball last week, we ended up losing the match. How is your MBA course going on?

Me: It is very hectic,the last 2 weeks passed by just like 2 days. There are lot of activities to get yourselves involved in. But I am liking it.

Sagar: It is good that you are enjoying. Looks like we have to find a new bowler for our team :(. What is it that you are working on rite now?

Me: I am working on an assignment on System architecture. Let me tell you it is a very interesting subject. I am sure you would also like it as you are inclined towards computers.

Sagar: Hmm..it does sound interesting. Can you please elaborate on what it is?

Me: Sure. System architecture is the conceptual model that defines the structure and behavior of a system. Simply put it is a representation on how a system is organized.

Sagar: I am not quite getting it. All of use a desktop/laptop, so you mean system organization is about how these are organized?

Me: Basically we use a lot of applications which in turn need data. So depending upon where this data and applications are stored there are 4 different types of architectures.

a. Single tier architecture

b.Two tier architecture

c.Three tier architecture

d.Multi tier architecture

a. Single Tier Architecture: In this both the data and applications are stored on the same machine, but the data will be separate from the application even though they are stored on the same physical drive.

Sagar: OK, so is Microsoft word and excel an example of this?

Me: Exactly. Not only those even the movies and songs we play can be used as an example for this. You need an application to play the movie/song, and that application has to be installed in your machine.

b. Two tier architecture: The single tier architecture has limitations, to overcome those this 2 tier architecture is developed. It is also called client server architecture. 

In this architecture the data and the application are stored in separate locations. Consider an example, there are 1000 employees who need to access same data(100 GB). If you follow single tier architecture then you will have to copy the 100 GB in all the 1000 machines which is a waste of space.So here the data is stored in a location called a database which is accessed by the users who need it.

 

Sagar: So all the users are clients and the database can be called a server. All the clients and server should be connected rite?

Me: Yes you are correct. They are connected using a TCP/IP protocol. One of the disadvantages of this architecture is performance and requirement of high bandwidth.

c.3 Tier Architecture: In this type of architecture the business logic is separated from the front end part of the application. So the data, business, GUI applications reside on separate machines. Contrary to 2-tier architecture if you want to change the business logic you don't have to modify on each and every machine. 

  

d.Multi Tier Architecture : It is very similar to 3-tier architecture, only difference is internet is used to communicate between clients and servers. This enhances the performance, all the systems need not be in the same network or physically connected to each other. We just need access to internet which will connect to a web server to get our request done.

Sagar: Interesting, how is the security achieved?

Me: We achieve security using Firewall when we connect to internet.

Sagar: OK. I will go through these concepts again and will contact you in case of any doubts. Thank you for the information.

Me : You are welcome. Bye.

Sagar: Bye.