CodeIgniter is an elegant open-source software web framework and it is based on the model-view-controller (MVC) development pattern. Codeigniter is popular and widely accepted because its light, easy to code and highly flexible. Instead of having to write codes from the scratch in order to get a website developed, this framework contains templates of commonly needed tasks in a library which developers can build upon.
CodeIgniter framework was originally developed in 2006 by Rick Ellis. It was originally written by EllisLab flagship CMS to function as a collection of refactored classes. It is now being used by thousands of PHP developers all over the world to get tasks done fast.