Those who are in control of the external energy of the Lord, or in other words those who are in the material world, must first of all know how the external energy of the Lord is working under the direction of the Supreme Personality, and afterwards one may try to enter into the activities of His internal energy. The mundaners are mostly worshipers ofDurgā-devī, the external energy of Kṛṣṇa, but they do not know that Durgā-devī is but the shadow energy of the Lord. Behind her astonishing display of material workings is the direction of the Lord, as confirmed in the Bhagavad-gītā (9.10). The Brahma-saṁhitā affirms that Durgā-śakti is working by the direction of Govinda, and without His sanction the powerful Durgā-śakti cannot move even a blade of grass.
(Srimad Bhagavatam----2:4:6----purport).

Lord Śiva is so great that he does not care for the material prosperity for which every one of us is so eager. Pārvatī, who is the powerful material nature personified, is under his full control as his wife, yet he does not use her even to build a residential house. He prefers to remain without shelter, and his great wife also agrees to live with him humbly. People in general worship goddess Durgā, the wife of Lord Śiva, for material prosperity, but Lord Śiva engages her in his service without material desire. He simply advises his great wife that of all kinds of worship, the worship of Viṣṇu is the highest, and greater than that is the worship of a great devotee or anything in relation with Viṣṇu.
(Srimad Bhagavatam----3:14:26----purport).

Lord Śiva is the husband of Durgā, the controller of the material energy. Durgā is personified material energy, and Lord Śiva, being her husband, is the controller of the material energy.
(Srimad Bhagavatam----3:14:29----purport).

According to a verse of the Vedic mantras, parāsya śaktir vividhaiva śrūyate: (Cc. Madhya 13.65, purport) the Supreme Personality of Godhead has different varieties of energies. Sakti is feminine, and the Lord is puruṣa, masculine. It is the duty of the female to serve under the supreme puruṣa. As stated in Bhagavad-gītā, all living entities are marginal energies of the Supreme Lord. Therefore it is the duty of all living entities to serve this Supreme Person. Durgā is the representation in the material world of both the marginal and external energies, and Lord Śiva is the representation of the Supreme Person. The connection of Lord Śiva and Ambikā, or Durgā, is eternal. Satī could not accept any husband but Lord Śiva. How Lord Śiva remarried Durgā as Himavatī, the daughter of the Himalayas, and how Kārttikeya was born, is a great story in itself.
(Srimad Bhagavatam----4:7:59----purport).

Herein it is mentioned that Lord Śiva is always accompanied by his material energy (śaktyā ghorayā). Material energy—goddess Durgā, or goddess Kālī—is always under his control.Goddess Kālī and Durgā serve him by killing all the asuras, or demons. Sometimes Kālī becomes so infuriated that she indiscriminately kills all kinds of asuras. There is a popular picture ofgoddess Kālī in which she wears a garland composed of the heads of the asuras and holds in her left hand a captured head and in her right hand a great khaḍga, or chopper, for killing asuras. Great wars are symbolic representations of Kālī's devastation of the asuras and are actually conducted by the goddess Kālī.
sṛṣṭi-sthiti-pralaya-sādhana-śaktir ekā
(Bs. 5.44)
Asuras try to pacify the goddess Kālī, or Durgā, by worshiping her in material opulence, but when the asuras become too intolerable, goddess Kālī does not discriminate in killing them wholesale. Asuras do not know the secret of the energy of Lord Śiva, and they prefer to worship goddess Kālī or Durgā or Lord Śiva for material benefit. Due to their demoniac character, they are reluctant to surrender to Lord Kṛṣṇa, as indicated by Bhagavad-gītā (7.15):
na māṁ duṣkṛtino mūḍhāḥ
prapadyante narādhamāḥ
māyayāpahṛta-jñānā
āsuraṁ bhāvam āśritāḥ
Lord Śiva's duty is very dangerous because he has to employ the energy of goddess Kālī (or Durgā). In another popular picture the goddess Kālī is sometimes seen standing on the prostrate body of Lord Śiva, which indicates that sometimes Lord Śiva has to fall down flat in order to stop goddess Kālī from killing the asuras. Since Lord Śiva controls the great material energy (goddess Durgā), worshipers of Lord Śiva attain very opulent positions within this material world.
(Srimad Bhagavatam----4:24:18----purport).

The question of how the planets and stars are floating is also answered in this verse. It is not because of the laws of gravity. Rather, the planets and stars are enabled to float by manipulations of the air. It is due to such manipulations that big, heavy clouds float and big eagles fly in the sky. Modern airplanes like the 747 jet aircraft work in a similar way: by controlling the air, they float high in the sky, resisting the tendency to fall to earth. Such adjustments of the air are all made possible by the cooperation of the principles of puruṣa (male) and prakṛti (female). By the cooperation of material nature, which is considered to be prakṛti, and the Supreme Personality of Godhead, who is considered the puruṣa, all the affairs of the universe are going on nicely in their proper order. prakṛti, material nature, is also described in the Brahma-saṁhitā (5.44) as follows:
sṛṣṭi-sthiti-pralaya-sādhana-śaktir ekā
chāyeva yasya bhuvanāni bibharti durgā
icchānurūpam api yasya ca ceṣṭate sā
govindam ādi-puruṣaṁ tam ahaṁ bhajāmi
"The external potency, māyā, who is of the nature of the shadow of the cit (spiritual) potency, is worshiped by all people as Durgā, the creating, preserving and destroying agency of this mundane world. I adore the primeval Lord Govinda, in accordance with whose will Durgā conducts herself." Material nature, the external energy of the Supreme Lord, is also known asDurgā, or the female energy that protects the great fort of this universe. The word Durgā also means fort. This universe is just like a great fort in which all the conditioned souls are kept, and they cannot leave it unless they are liberated by the mercy of the Supreme Personality of Godhead.
(Srimad Bhagavatam----5:23:3----purport).

Because Citraketu was undoubtedly a Vaiṣṇava, he might have been surprised that Pārvatī had cursed him. Therefore the goddess Pārvatī addressed him as putra, or son. Everyone is the son of mother Durgā, but she is not an ordinary mother. As soon as there is a small discrepancy in a demon's behavior, mother Durgā immediately punishes the demon so that he may come to his senses. This is explained by Lord Kṛṣṇa in Bhagavad-gītā (7.14):
daivī hy eṣā guṇa-mayī
mama māyā duratyayā
mām eva ye prapadyante
māyām etāṁ taranti te
"This divine energy of Mine, consisting of the three modes of material nature, is difficult to overcome. But those who have surrendered unto Me can easily cross beyond it." To surrender to Kṛṣṇa means to surrender to His devotees also, for no one can be a proper servant of Kṛṣṇa unless he is a proper servant of a devotee. Chāḍiyā vaiṣṇava-sevā nistāra pāyeche kebā: without serving a servant of Kṛṣṇa, one cannot be elevated to being a servant of Kṛṣṇa Himself. Therefore mother Pārvatī spoke to Citraketu exactly like a mother who says to her naughty child, "My dear child, I am punishing you so that you won't do anything like this again." This tendency of a mother to punish her child is found even in mother Yaśodā, who became the mother of the Supreme Personality of Godhead. Mother Yaśodā punished Kṛṣṇa by binding Him and showing Him a stick. Thus it is the duty of a mother to chastise her beloved son, even in the case of the Supreme Lord. It is to be understood that mother Durgā was justified in punishing Citraketu. This punishment was a boon to Citraketu because after taking birth as the demon Vṛtrāsura, he was promoted directly to Vaikuṇṭha.
(Srimad Bhagavatam----6:17:15----purport).

The names by which Māyādevī is known in different places have been listed by Vallabhācārya as follows. In Vārāṇasī she is known as Durgā, in Avantī she is known as Bhadrakālī, in Orissa she is known as Vijayā, and in Kulahāpura she is known as Vaiṣṇavī or Mahālakṣmī. (The representatives of Mahālakṣmī and Ambikā are present in Bombay.) In the country known as Kāmarūpa she is known as Caṇḍikā, in Northern India as Śāradā, and in Cape Comorin as Kanyakā. Thus she is distributed according to various names in various places.
(Srimad Bhagavatam----10:2:11-12----purport).

Śrīla Vijayadhvaja Tīrthapāda, in his Pada-ratnāvalī-ṭīkā, has explained the meanings of the different representations. Māyā is known as Durgā because she is approached with great difficulty, as Bhadrā because she is auspicious, and as Kālī because she is deep blue. Because she is the most powerful energy, she is known as Vijayā; because she is one of the different energies of Viṣṇu, she is known as Vaiṣṇavī; and because she enjoys in this material world and gives facilities for material enjoyment, she is known as Kumudā. Because she is very severe to her enemies, the asuras, she is known as Caṇḍikā, and because she gives all sorts of material facilities, she is called Kṛṣṇā. In this way the material energy is differently named and situated in different places on the surface of the globe.
(Srimad Bhagavatam----10:2:11-12----purport).

Kaṁsa was astonished because the goddess Durgā had become the daughter of Devakī. Since Devakī was a human being, how could the goddess Durgā become her daughter? This was one cause of his astonishment. Also, how is it that the eighth child of Devakī was a female? This also astonished him. Asuras are generally devotees of mother Durgā, Śakti, or of demigods, especially Lord Śiva. The appearance of Durgā in her original eight-armed feature, holding various weapons, immediately changed Kaṁsa's mind about Devakī's being an ordinary human. Devakī must have had some transcendental qualities; otherwise why would the goddess Durgā have taken birth from her womb? Under the circumstances, Kaṁsa, struck with wonder, wanted to compensate for his atrocities against his sister Devakī.
(Srimad Bhagavatam----10:4:14----purport).

After speaking to Kaṁsa in this way, the goddess Durgā, Yogamāyā, appeared in different places, such as Vārāṇasī, and became celebrated by different names, such as Annapūrṇā, Durgā, Kālī and Bhadrā.
The goddess Durgā is celebrated in Calcutta as Kālī, in Bombay as Mumbādevī, in Vārāṇasī as Annapūrṇā, in Cuttack as Bhadrakālī and in Ahmedabad as Bhadrā. Thus in different places she is known by different names. Her devotees are known as śāktas, or worshipers of the energy of the Supreme Personality of Godhead, whereas worshipers of the Supreme Personality of Godhead Himself are called Vaiṣṇavas. Vaiṣṇavas are destined to return home, back to Godhead, in the spiritual world, whereas the śāktas are destined to live within this material world to enjoy different types of material happiness. In the material world, the living entity must accept different types of bodies. Bhrāmayan sarva-bhūtāni yantrārūḍhāni māyayā (B.G.18:61). According to the living entity's desire, Yogamāyā, or Māyā, the goddess Durgā, gives him a particular type of body, which is mentioned as yantra, a machine.
(Srimad Bhagavatam----10:4:13----translation and purport).