CodeIgniter,is a most powerful part of PHP framework which has very small footprint. Advantage is that it is simple in use and elegant toolkit such that to create full-featured web applications. This PHP framework is used by web development companies which deals with shared hosting accounts and meet the deadlines . It is a fit for large and undocumented framework. Main purpose of this toolkit is to help the coders to develop projects much faster than writing code from scratch. It provides a set of libraries. With this, web development companies can creatively focus on projects as this is a toolkit effective that minimizes the amount of code required for doing a particular task.If you use PHP for designing your site.It has inbuilt library classes.