Summary

In this chapter, you learned about an essential component of a web application – the Request-Response cycle of an application. You parsed the most commonly used HTTP methods and you are now able to tell the difference between them. You learned about best practices in terms of data security, code organization, and recommended approaches. You can perform data sanitization and validation as well, and you know how to upload files on a server, authenticate a user, and use a session, among other things. And, of course, you learned how to bootstrap all the examples into a practical piece – a web application.

We are not done just yet. Data persistence was mentioned several times during this chapter and not in vain. Data persistence is used by every application and represents the essence of why applications exist – to collect, process, and store data. Although we have stored data in this chapter's exercises as well (for example, in sessions or cookies),...