CodeIgniter is a powerful web framework for the PHP language. It has very high performance, in addition to being quite light. The framework is also quite secure as it prevents the developed application from the most common attacks present in web applications such as SQL Injection and Cross-Site Scripting (XSS), for example.
The framework makes the development of applications much easier, as it has several types of libraries and helpers that help in the development. This framework works with the MVC pattern (Model-View-Controller), a code structuring pattern that is very widespread nowadays, present in practically all current frameworks. In this pattern, the application is divided into three parts: controllers (logical part), models (interaction with the database) and views (application interface).
The recommended PHP version for using this framework is 7.3 or higher.