Usually parse functions convert the data from one type into another type. Example: string to number, number to string.

We should add in a debug function for ease of use. When  the  debug  function  is called , we want  to  echo  out  the  URL  of  the  last  API  call , and  the  HTTP  Status  Code.

A CodeIgniter hooks feature provides a means to tap into and modify the inner workings of the Codeigniter framework without hacking the core files. The hooks features can be globally enabled/disabled by—
                                $config [‘enable hooks’] =TRUE;

The thumbnail function will simply resize the original image to smaller so that the browsers are capable to load it fast as an icon.
$this->image_lib->resize();

If controller contains a function named _remap(), it will always get called regardless of what URI contains. It overrides the normal behavior in which the URI determines which function is called, allowing us to define our own function routing rules.