Lesson 3 of Amplify Your Coding: Mastering Web Apps with CodeIgniter 3 takes you deeper into the functionalities that make CodeIgniter a powerful tool for web developers. In this lesson, we focus on the features that streamline the development process and enable you to craft a more interactive and user-friendly web experience. From addressing the essentials of routing to managing file uploads, each topic is tailored to augment your web development prowess within the CodeIgniter framework.

Firstly, we'll unravel the mechanisms behind Routing and URL Creating in CodeIgniter 3, which are pivotal for navigating your web application. You will learn how to implement clean, organized URLs that enhance the user experience and contribute to search engine optimization. Following routing, we will explore the creation and implementation of Libraries in CodeIgniter 3, empowering your projects with reusable code that can elevate its efficiency and functionality.

Beyond libraries, Creating and Using Helpers in CodeIgniter is another step toward writing lean code. Helpers provide convenience and simplification, allowing you to perform common tasks without redundant coding efforts. Transitioning from backend to frontend considerations, the lesson will then guide you through Building Forms with Form Helper, detailing how you can create secure and robust forms with ease and reliability using CodeIgniter's built-in helpers.

Moreover, we'll delve into Data Handling with Input Class, an essential skill for handling user input securely and effectively. With an emphasis on security and best practices, this segment underpins the importance of clean data processing. The final segment, File Uploading with File Uploading Class, will encompass the procedures and nuances of handling user-uploaded content securely and swiftly. By the end of this lesson, your skillset will be enriched with essential techniques for achieving a scalable and secure web application worthy of today's dynamic online environment.