The most awaited time of the year in West Bengal is none other than the month of durgotsav. Durga puja festival is also the largest festival of Bengalis as well as of West Bengal. West Bengal is the birthplace of Durga puja festival. Later this festival spread across eastern Indian states like Assam, Odisha, Bihar from West Bengal . So before discussing more on the topic we firstly should know who actually is Durga Devi.

It is very clear through shastras that Durga Devi came into existence by the special yagna performed by Lord Vishnu ,Lord Shiva and Lord Brahma , but the manifestation of Devi Durga is very rarely understood because her manifestation is not as one it is actually dual in nature one known as Yogamaya and another is known as Mahamaya if one accepts this dual nature of durga devi it becomes very clear to understand her nature, Yogamaya is the personal potency of Lord Krishna’s energy and Mahamaya is originated from Yogamaya itself .

Role of Yogamaya and Mahamaya
Yogamaya is that form of Devi Durga which actually shows her nature of a caring Mother who loves and bestows them the required facilities to progress in spiritual life easily and does activities which cleanse the heart of a practicing devotee which most of the time initially seems to be very harsh in nature but it is for the benefit of the Devotee only this cannot be understood just by mere philosophical words it can actually be understood by the one who has actually experienced it in his or her life.
She actually helps to establishes the friend or son like relation with Lord Krishna.
Bhagavatam Canto 9 Chapter 2 states about Durga devi :
She bestows on Lord Krishna’s Devotees, pure devotion towards Lord Krishna , She is the Vaisnavî Shakti of the Vaishnavas. She gives final liberation to those that want such and gives happiness to those that want happiness.

Mahamaya is that form of devi durga which simply can be defined as the mother who get very angry when her child totally follows the wrong path in his or her life she ten only focuses on punishing them for their bad deeds having said that it should be also kept in mind that Mahamaya also has affection and love for those children even and she deals with them in a manner which makes the child realise his faults very soon it can simply be compared to as a tuition teacher who slaps her pupil so that he or she continues to do his or her homework regularly so that he excels in his exams, not for the benefit of the teacher but for the benefit of the child’s future .

All illusion is created by Mahamaya she is the stage developer behind the false enjoyment of a living being and his miseries due to his sense gratification but this aspect is not seen in Yogamaya.
Yogamaya only plays her role in the spiritual world having said that it should also be noted that she has the potency to control Mahamaya and it is only done so if instructed by Lord Krishna himself it generally takes place only in case of good practicing Devotees and of course with Pure Devotees . Actually when a Devotee while practicing devotion to Lord Krishna he initially is disturbed by Mahamaya until all his desires(of sense gratification) are not burnt away after that Lord Krishna himself instructs to Yogamaya and Yogamaya to Mahamaya to remove her all illusionary energy from the Devotees surrounding so that he can attain perfection in devotion without any further obstacles created by illusionary energy of Mahamaya
But the story of illusions does not end here it even continues in the spiritual world but in a very special manner lets try and understand this in the spiritual world Yogamaya covers the pure liberated souls with her power in the Lila with her power of illusion such that they are unaware of krishna’s real nature and thus relate to him not as God but rather as his friend, lover, or child and so on .If Yogamaya will not extend her illusion in this way, the souls would realise Krishna’s real nature and be incapable of interacting with him in Lila in this intimate ways this can be simply understood as if the Devotee new that Lord Krishna is God then who would actually accept him as his son or friend knowing well that this is the same Lord who himself has created them therefore unlike that of Mahamaya , Yogamaya’s illusionary energy is a highly desirable and positive one obtained by highest yogis and perfect devotees.

SUMMARY
Nowadays people relate Durga Devi as a sister of Lord Krishna but this is not totally wrong this is applicable only specifically for the vrindavan lila of Lord Krishna and not for the actual spiritual world that is Golakadham there Devi Durga resides as a special form of Mother Radha Rani’s special illusionary potency
which has two forms. One is Maha-maya. She is the goddess who governs the material worlds. Another one is Yoga-maya and She governs the spiritual worlds. Together they form the female aspects of God. So Krishna’s illusory energy, Maya, Mother Nature, is a woman. Maya’s husband is Shiva. Krishna never touches matter, but when he has to, He transforms into Shiva. Shiva is a transformation of Krishna and Maya is a transformation of Radha and through the union of Maya and Shiva, the material world is created. The spiritual world is not created, it is manifested forever by the union of Radha and Krishna
I would like to end this article by stating one sloka of Bhagavad Gita where Lord Krishna says as follows

All states of being—be they of goodness, passion or ignorance—are manifested by My energy. I am, in one sense, everything—but I am independent. I am not under the modes of material nature. (Bhagavad-gita 7.12)
PURPORT
All material activities in the world are being conducted under the three modes of material nature. Although these material modes of nature are emanations from the Supreme Lord, Krishna, He is not subject to them.
Under the state laws one may be punished, but the king, the lawmaker, is not subject to that law. Similarly, all the modes of material nature—goodness, passion and ignorance—are emanations from the Supreme Lord Krishna, but Krishna is not subject to material nature. Therefore these modes of nature, although issuing from Him, do not affect Him. That is one of the special characteristics of Bhagavan, or the Supreme Personality of Godhead.