Drivers are a special type of Library that has a parent class and any number of potential child classes. Child classes have access to the parent class, but not their siblings. Drivers provide an elegant syntax in your :doc:`controllers <controllers>` for libraries that benefit from or require being broken down into discrete classes.
Drivers are found in the system/libraries/ directory, in their own sub-directory which is identically named to the parent library class. Also inside that directory is a subdirectory named drivers, which contains all of the possible child class files.
To use a driver you will initialize it within a controller using the following initialization method:
$this->load->driver('class_name');
Where class name is the name of the driver class you want to invoke. For example, to load a driver named "Some_parent" you would do this:
$this->load->driver('some_parent');
Methods of that class can then be invoked with:
$this->some_parent->some_method();
The child classes, the drivers themselves, can then be called directly through the parent class, without initializing them:
$this->some_parent->child_one->some_method(); $this->some_parent->child_two->another_method();
Please read the section of the user guide that discusses how to :doc:`create your own drivers <creating_drivers>`.