This document provides an overview of the CodeIgniter PHP framework. It discusses what a framework is and describes CodeIgniter's MVC architecture. The Model-View-Controller pattern separates application logic from presentation. CodeIgniter offers features like form validation, security filtering, and database classes. It is lightweight, fast, extensible and well documented. Basic installation involves downloading CodeIgniter files and configuring them on a local server. The document also lists modules for a sample "News Blog" project built with CodeIgniter.