Question:  Explain what is CodeIgniter?
Answer :    Codeigniter is an open source framework for web application. It is used to develop   websites on PHP. It is loosely based on MVC pattern, and it is easy to use compare to other PHP framework.

Question:  Explain routing in CodeIgniter?
Answer :   In CodeIgniter, the way PHP files served is different rather than accessing it directly  from the browser. This process is called routing. Routing in CodeIgniter gives you freedom to customize the default URL pattern to use our own URL pattern according to the requirement. So, whenever there is a request made and matches our URL pattern it will automatically direct to the specified controller and  function.  

Question:  Explain what are hooks in CodeIgniter?
Answer :    CodeIgniter hooks provides a way to change the inner working of framework without   hacking the core file. It facilitate us to execute a script with a particular path within the  CodeIgniter. Basically , Hooks defined in.. application/config/hooks.php file.

Question:  What are the feature of CodeIgniter?
Answer :   List of CodeIgniter feature..
                   a) It's an open source and free to use framework.
                   b) Extremely Light weighted.
                   c) It's based on Model View Controller (MVC) Pattern.
                   d) Full featured database classes supports for several platforms.
                   e) Extensible, Means you can easily extend the system by using libraries, helpers.
                   f)  Excellent Documentation.

Question:  How can load / add model in CodeIgniter?
Answer :    By using th following function...
                   $this->load->model('model_name');

Question:  Explain Views in CodeIgniter?
Answer :    View folder contains all the markup files like header, footer, sidebar etc. All view file can be reused by embedding them anywhere in controller file. View file can't called  directly, they have to be called in the controller file.

Question:  How can load a view file in CodeIgniter?
Answer :    View's files can't be accessed directly. These are loaded in the controller.
                   $this->load->view('view_file_name');


Question:  Explain Controller in CodeIgniter?
Answer :    A controller is a intermediary between model and views to process HTTP request to generate web page. It is a center of every request in application.

Question:  Define Basic CodeIgniter Url Structure?
Answer :    CodeIgniter uses 'Segment Based' Approach instead of 'Query String' Approach.
                   CodeIgniter Url Structure As Follows....
                   abc.com/class_name/function_name/Id
                   class_name represent controller class that needs to be invoked.
                   function_name is the method or function that is called.
                   Id is a additional segment that is passed to controllers.

Question:  Explain Codeigniter architecture?