Sanjay Mehta ji explained this.
Navaratri
Nine nights/days of Shakti Puja/Upāsanā.
Vrat and Upavās
Yajurved says, "व्रतेन दीक्षामाप्नोति – Vraten Deekshamapnoti" – by observing Vrat one reaches purity, perfection, and agility. The word ‘vrat’ is derived from the Sanskrit root word which means obedience or duty, right choice, solemn vow or undertaking.
Upavās is a Sanskrit word, meaning the attainment of mental proximity with the Bhagwan. Vrat is also translated as fasting. In Vrat one resolves not to eat or to abstain from certain foods and acts, for a specified period.
Vrat and Upavās result in:
- Elimination of negative tendencies
- Raised self-awareness
- Elevation on spiritual path
What heat does to food in cooking, Vrat (Tapas) does to mind in self-development/spiritual development. (From HMEC publ. - Hindu Vrat book)
How to observe Navaratri Vrat?
Pick any slot of four, six, eight or more hours for fasting during the day for nine days. It is ok to drink water, milk, or juice to maintain energy level during fasting period. Chant the following mantra (nine chants) as many times possible during the day, at least once in Puja place at home.
- Yaa
Devi Sarva-Bhuteshu Shakti-Roopena - शक्तिरूपेण
Samsthitaa,
Namas-Tasyai Namas-Tasyai Namas-Tasyai Namo Namah.
या
देवी भूतेषु शक्तिरूपेण संस्थिता, नमस्तस्यै नमस्तस्यै नमस्तस्यै नमो नमः
My pranam to Devi who abides in me
and all beings in the form of Strength/fearlessness.
- Yaa
Devi Sarva-Bhuteshu Buddhi-Roopena – बुद्धिरूपेण
Samsthitaa,
Namas-Tasyai Namas-Tasyai Namas-Tasyai Namo Namah.
My pranam to Devi who abides in me
and all beings in the form of Discriminative power/wisdom.
- Yaa
Devi Sarva-Bhuteshu Lakshmi-Roopena – लक्ष्मीरूपेण Samsthitaa,
Namas-Tasyai Namas-Tasyai Namas-Tasyai Namo Namah.
My pranam to Devi who abides in me
and all beings in the form of Prosperity.
- Yaa
Devi Sarva-Bhuteshu Kshaanti-Roopena - क्षान्तिरूपेण
Samsthitaa,
Namas-Tasyai Namas-Tasyai Namas-Tasyai Namo Namah.
My pranam to Devi who abides in me
and all beings in the form of Forbearance.
- Yaa
Devi Sarva-Bhuteshu Shraddha-Roopena – श्रद्धारूपेण
Samsthitaa,
Namas-Tasyai Namas-Tasyai Namas-Tasyai Namo Namah.
My pranam to Devi who abides in me
and all beings in the form of Reverence.
- Yaa
Devi Sarva-Bhuteshu Kaanti-Roopena - कान्तिरूपेण
Samsthitaa,
Namas-Tasyai Namas-Tasyai Namas-Tasyai Namo Namah.
My pranam to Devi who abides in me
and all beings in the form of Beauty.
- Yaa
Devi Sarva-Bhuteshu Tushti-Roopena - तुष्टिरूपेण
Samsthitaa,
Namas-Tasyai Namas-Tasyai Namas-Tasyai Namo Namah.
My pranam to Devi who abides in me
and all beings in the form of Contentment.
- Yaa
Devi Sarva-Bhuteshu Dayaa-Roopena – दयारूपेण
Samsthitaa,
Namas-Tasyai Namas-Tasyai Namas-Tasyai Namo Namah.
My pranam to Devi who abides in me
and all beings in the form of Kindness.
- Yaa
Devi Sarva-Bhuteshu Shanti-Roopena - शान्तिरूपेण
Samsthitaa,
Namas-Tasyai Namas-Tasyai Namas-Tasyai Namo Namah.
The Mother/Devi/Mata is worshiped in three forms:
- as Durga, who destroys all impurities, negativities, and fear. (grants Abhaya - अभय)
- as Lakshmi, who bestows prosperity and the right objective. (grants Samrddhi - समृद्धि)
- as Saraswati, who bestows knowledge and wisdom (grants Viveka-Buddhi – विवेक-बुद्धि)
Nine days of Puja / Upaasana of nine manifestations (Roop):
- शैलपुत्री
- ब्रह्मचारिणी
- चंद्रघंटा
- कूष्मांडा
- स्कंदमाता
- कात्यायनी
- कालरात्रि
- महागौरी
- सिद्धिदात्री
Day 1: Shailaputri: An embodiment of tapas and perseverance
Day 2: Brahmcharini: An embodiment of austerity
Day 3: Chandraghanta: An embodiment of beauty
Day 4: Kushmanda: An embodiment of the creative power of universe
Day 5: Skandmata: An embodiment of motherly love, mother of Skand(or Kartikeya).
Day 6: Katyayani: An embodiment of courage.
Day 7: Kalratri: An embodiment of ferocious (for demons)
Day 8: Mahagauri: An embodiment of intelligence and peace.
Day 9: Siddhidatri: An embodiment of supernatural powers (Siddhi)
First three days, the Mother/Devi is adored as supreme power and force, as Durga to destroy all impurities and fear. (overcome Tamo Guna)
Next three days, the Mother/Devi is adored as the bestower of spiritual wealth, as Lakshmi. (Rajo Guna)
Last three days, the Mother/Devi is adored as the bestower supreme wisdom/ divine knowledge, as Saraswati. (Acquire Sattva Guna)
Significance of Tithis:
Pratipada, Shashti, Ekadashi - Nanda: Delight, happiness
Dwitiya, Saptami, Dwadashi - Bhadra: Auspicious, fortunate
Tritiya, Ashtami, Trayodashi - Jaya: Conquest, victory
Chaturthi, Navami, Chaturdashi - Rikta: Peace, quietude
Panchami, Dashami, Purnima - Purna: Fulfilled, accomplished.