The festival of Navaratri ("nine nights”) is a worship of the divine mother Durga in several forms. Each night a puja is held, and there is chanting of the Navarna Mantra, "Om aim hreem kleem chaamundaayai viche namah". Durga alsohelps you to protect your spiritual practice from the distractions and pitfalls that you encounter regularly in worldly life. This link http://www.dlshq.org/religions/navaratri.htm is to Swami Sivananda's explanation of Durga Puja or Navaratri.
