SQL injection is a technique, or you could say, an expert technique, that is used to steal data by taking advantage of a nonvalidated input vulnerability. The method by which a web application works can be seen in the following screenshot:
The method by which a web application works
If our query were not validated, then it would go to the database for execution, and then it might reveal sensitive data or delete data. How data-driven websites work is shown in the preceding screenshot. In this screenshot, we are shown that the client opens the web page on a local computer. The host is connected to a web server via the internet. The preceding screenshot clearly shows the method by which the web application interacts with the database of a web server.
