 Now dear students, database technology and databases have been around for a long time. But the web is relatively new, relatively new, not very new. So what has happened is that the web and the technology has given a shot in the arm of the old technology and web enables the dissemination that transfer the exchange of data for the database applications which can be anywhere in the world across the globe. So it's kind of a win-win combination of the database technology and the web technology. Now as we speak, literally hundreds and thousands of new users are coming up on the internet, are joining the web with a tremendous market for the web-based database applications and that is why you are taking this course. So in this module I will briefly give the objectives and some of the introduction. So let's go ahead. So I'll talk about the basic concepts which you may be knowing and static versus dynamic web page that is very important because that you might not be knowing. That is why you are taking this course. Web-based versus the client server-based traditional applications. I will do a comparison. I will show you a table also and then the important concerns, the important concerns of using web-based database applications, which is the network, which is the security, the transmission and so on. So let's go into more details. So these are the basic concepts. Everybody knows or usually knows what internet is, what the web is and what intranet is, extranet is. So intranet is something very big. It is very, very big. This is internet. And intranet is a network within an organization which is accessible to the users of that organization. That is the intranet. And extranet is allowing the outside traffic from the internet coming on the intranet. So if you use the Venn diagram over here like this, so this is the internet and this is the intranet and this is the extranet. I believe you understand. Now there are two types of web pages, static versus dynamic. Static pages is that you type something in a web page and you store it somewhere and that's it. That's a static page. Whenever you make a click or read it, its contents will never change. That is a static page. That's not very interesting. That is not very useful unless of course it's like history. History never changes. So you can have a static web page for history or for policies but the policies can change also. So you have these dynamic pages. Dynamic pages are generated on the go. I will explain it to you. So static versus dynamic pages. What happens that dynamic pages are more versatile? Dynamic pages you can make a request to get something and the dynamic pages are generated which contain the contents as per your request. You can create an environment for yourself using dynamic pages. Dynamic pages are easy to maintain also and so on. You can of course add some static material to dynamic pages also. So you write the script which generate the dynamic pages on the go. On the go means that as you are proceeding to view and explore a website, those web pages are generated. They are not static. They were not there. They are generated as per your need, as per your requirement, as per your commands, as per your clicks. You understand what I'm saying? So let's take a look at this diagram also. So I click on something over here and this click goes over here to the internet and then comes over here. Okay. Maybe I would like to know about a certain product and or I would like to know the status of the grade of a student. So this request goes all the way to the database. And from the database, a page is generated or the data is passed. Okay. And it goes over there. It goes over there. Okay. And maybe if there's a warning that the frame becomes red or orange, or if it's okay, it becomes green, or there's a congratulatory message and so on. And this page basically is displayed over here. So I have this dynamic page generated on the go. Now web based versus client server applications, details are in the notes, of course, so I will not go through all of them. It is platform dependent, the client server is platform dependent, the client, the traditional client server application, right? So if the application has to change, you add something to it, try to understand you add something to it. Maybe you have to make the changes at all the clients is very expensive. That is going to take a lot of resources. But this is platform independent. Okay, web based applications are platform independent. You can be running them in a different operating system in a different browser, because there are certain standards which are built there. You have to install a traditional client server application. It means that the user base is very small. No need for installation. If you have say 500 million internet users potential users, they just click on your website. There's no need to install. But a traditional client server application, it's not possible to install it at 500 million handheld devices or computers difficult to integrate, but is easy to integrate. And the list goes on persistent connection. This is a very, very strong benefit of traditional persistent connection, which is more secure, gives high performance over here non persistent web does not remembers your connection, even if coming from the same location and so on. And finally, the reliability of the internet packets drop congestion, right, or a link down and so on. So the network traffic is not reliable, is not reliable. You cannot ensure a desired level of response, which is guaranteed in a traditional client server environment and the security. People can break into banks into your databases, they can steal data, they can use ransomware, they can do many things, and they can intercept the traffic going from point A to point B. This traffic can be intercepted. However, work is going on to handle these issues. And these issues will be handled. And the web based database applications will be more reliable and more secure. That is a lesson you should take today from this module. Thank you very much.