Magento:: Session and Cookie handling

Magento provides very easy way to handle Cookie and session.
Magento session:
    >> Magento session is handle by core Module 'core/session'. Here is the way to save Session in magento

            $session = Mage::getSingleton("core/session");

            $session->setData("username", "value");     //This will store a session variable name "username"
                            OR
            $session->setUsername("value");
           
            To get This session value we can use one of these following ---
           
            $session->getData("username");
                        OR
            $session->getUsername();
   
    >> And session can be removed with setting session variable null
   
            $session->setData("username", null);
            $session->setUsername("");
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Cookie Handling in Magento:
    >> Setting cookie
            Mage::app()->getCookie()->set('cookie_name', "cookie_value", $lifetime,$domain,$httponly);
    >> Getting cookie in magento
            Mage::app()->getCookie()->get('cookie_name');