 So, in this module, we'll talk about web database operations. In the 1940s, when the electronic computers were developed and designed by Alan Turing and Vaughan Newman, they distinctively said that the operations or the instructions in the computer program could alter the instructions and the data was also alterable by the instructions. Now, that created a lot of problems and, of course, that allowed to develop the computers and the revolution was there, but that created a lot of problems. And the requirement was to have a distinction between the data and the instructions. And that is where we come to the two different paradigms of the procedural programming and the database programming. And the data is considered different, separate from the instructions. Instructions separate, data separate, right? That was a requirement when the operating systems were introduced. But Vaughan Newman and Alan Turing, they wanted them to be treated not differently, but like similarly. So, let's proceed ahead and I'll go into more details. Now, when this problem occurred. So the approach was to separate the database application from the data itself. So nowadays, they are very, very different, they are separate. They are not alterable. The instructions don't alter the instructions. The instructions alter the database. So the event was of the procedural programming and the database programming. In the database programming, we separate the instructions from the database and in the procedural programming, the approach is different. So if you look at the results, which I'll show you, the approach, the coding approach and the results approach is very different for the procedural programming and for the database programming. And the code is written in a very different way. In database programming, we get the results and then we work on the results. The results which I'm talking about is the data which is provided by the database server. Now, why these differences are there, I've explained it to you. And I'll also talk about the data and nothing but the data. Now the screen which shows different topics, these topics will be covered when we go into the details of this particular module. This is the introductory module. I will just briefly dwell upon some of the topics which are more interesting, which are more requiring more detail, which will be I'll get into more detail in the next module. So what we have in procedural programming, in procedural programming, we have the procedures, we have the functions, we have the main function, which you can see on the screen that calls or the generates other procedures. And those procedures have more functions. And the program is divided into logical parts into logical steps. And it works on those logical steps in a sequential manner. And the results are generated and the results are processed and it becomes on your screen. So that is the procedural language. That is the procedure approach of solving the problem. The database approach of solving the problems is different. The different in the sense which I have explained earlier that the database is separated from the instructions. And the results, as they come up from one set of instructions, they are processed and used by the sequentially and in that manner. So these things will become clear as I explained to you in more detail. Now this screen shows you how the web page is generated. Now remember, which I have told you in the prior modules also that we are looking at the three tier architecture. So at one tier, we have the database server. At the second tier, we have the application program engine. And then we have the client tier. So what happens is that your data comes from the database server. And that is the query part that is the query part, which you can see on the screen. And that query part results and adds to the HTML part. So we have the HTML part, we have the query part and together they generate the page. And that page comes in front of you. So that is the way the page is generated. It is a combination of the text and it is a combination of the data results, which are also introduced as text and generate. There can be single query, there can be multiple queries also. Now this is the last slide for this module. It is data nothing but the data itself. Now there is a trap, trap in the sense that there is a short term approach. We have that static web page approach and we have that web application approach. So in the static web page approach, the text is the data or you write the text, for example, your name, your contact information. Contact information usually stays same, does not changes, right or not. And then you have other information also. So obviously it is simpler to add text to the web page as compared to entering data in a database, right? You understand this. The other problem or other short term benefit is that you don't have to design a database. Entering text in a page. Now the problem occurs when you have to update the page or maintain the page, right? Because then you have to make changes at many, many places and you can make mistakes while you make the changes and you can miss something. So short term approach, it looks fine. But in the long term approach, all the data which generates the page should go into a database. So you have to be very vigilant that you don't make the mistake of spending time or the short term approach of entering text in a web page and avoiding entering data in a database. So now you understand because once I have the data in the database, then of course what I can do is that I can dynamically generate the pages and it is very convenient.