CodeIgniter is a powerful open-source PHP framework with a very small footprint, created by Rick Ellis in 2006. CodeIgniter was born from ExpressionEngine, essentially a collection of refactored classes originally written for EllisLab's flagship CMS. Stripped of the application-specific functionality, CodeIgniter was made to be a simple and elegant toolkit, enabling rapid development of both web sites and web applications, attracting thousands of talented PHP developers.
CodeIgniter is an application development framework, which can be used to develop websites, using PHP. It is an Open Source framework. It has a very rich set of functionality, which will increase the speed of website development work.
If you know PHP well, then CodeIgniter will make your task easier. It has a very rich set of libraries and helpers. By using CodeIgniter, you will save a lot of time, if you are developing a website from scratch. Not only that, a website built in CodeIgniter is secure too, as it has the ability to prevent various attacks that take place through websites.
Some of the important features of CodeIgniter are listed below −
Model-View-Controller Based System
Extremely Light Weight
Full Featured database classes with support for several platforms
Query Builder Database Support
Form and Data Validation
Security and XSS Filtering
Email Sending Class. Supports Attachments, HTML/Text email, multiple protocols (sendmail, SMTP, and Mail) and more
Image Manipulation Library (cropping, resizing, rotating, etc.). Supports GD, ImageMagick, and NetPBM
File Uploading Class
Flexible URI Routing
Large library of “helper” functions