CodeIgniter is an open–source web application framework for developing dynamic web sites with PHP. It is based on the MVC (Model–View–Controller) architectural pattern. CodeIgniter provides a simple and elegant toolkit for creating full–featured web applications. It is designed to be lightweight, with a small footprint, and high performance. The framework has a very small footprint, requires nearly zero configuration, and is easy to set up and use. CodeIgniter also has a simple and intuitive interface, which makes it easy to learn and use.