There are 19 different types of Gopis who took part in singing the Gopi–Geet. The Gopis who came to Raas, were divided into nineteen different groups, and these nineteen divisions were also segregated into two categories, mainly Rushi rupa-Gopis (Rushis who came as Gopis) and Shruty rupa-Gopis (vedas who came as Gopis). The Veda Shruty, who were inclined to experience Brahma-ras (bliss) took salvation in Gopis form. These Vedas took the body of female and entered Vraj as Gopis. They were bestowed with the ability to love and cherish the ultimate permutation of love and affections. They came to Krishna with love and with ardent surrender to Him, they were able to achieve Krishna’s love.
These Gopis were expert on Vedas and also were well informed of the agility and ability portrayed by the form of a female. The famine aptitude and character were of three important ingredients and these ingredients are Sneha (love), Shradha (trust) and Samarpan (surrender). These Gopis knew that these feminine components of mixture was very important to gain access to Krishna’s heart, so they entered into female form. (That is why in the advanced bhaktas or devotees depicts feminine sakhi bhava, and Thakorji also adores this induced bhava).
Dandakarania Rushis (the rushis of the forest, Dandakarania during the Rama-avatar era) were impressed by Shree Raghunath (Rama’s) Madhuriya (exotic form) also decided to take female form and entered the Vraj. So these Rushis were known as Rushi Rupa-Gopis and the Veda ruchas (Ved-Shruty) were Shruty Rupa-Gopis.
Shruty Rupa-Gopis arrived in Vraj before Shree Krishna came to Vraj. So as these Gopis were first to arrive, they mixed and mingles with the Vraj vasi (local Vraj people), and they married Gopas of Vraj. So according to Vedic system, these Gopis belonged to Gopas; hence, they were classified as “others”.
Shree Mahaprabhu Vallabhacharya called these “other” Gopis as Anayapurva (Anaya= to other, purva=belongs) Gopis. Rushi Rupa-Gopis are Shree Krushna samkalin (were in the era pre Ram and Pre Krishna avatar. These were formed during Brahma Yagna by Brahmaji and are also known as Agni-kumarika. They were formed by essence of Agni (fire) of Yagna (a ritual where Brahma did an Yagna to acquire Brahm) These Agni-kumarika became Rushis and from Rushis, they took the female form of Vraj Gopis. So they were classified as Rushi-rupa-Gopis. These Rushi-rupa-Gopis did not marry any Vraj Gopas, and thus did not belong to “others”, and as they were not Anayapurva, Shree Vallabhacharya classified these Gopis as Ananyapurva.
Although our marriage is performed to anyone or we are still single, this element does not make any difference to Krishna. He will bestow his presence and grace to one & all. So Anayapurva and Ananyapurva Gopis were excepted in Maharaas and to Krishna, there was no distinction.
Shruty-rupa Gopis were of nine characters and so were Rushi-rupa-Gopis. The divisions in Maharaas was set according to their swabhava (essential nature) and the swabhava is created from Prakruti (nature). Prakruti is made of three qualities, Satvik (goodness), Rajas (activity) and Tamas (inactivity). In every quality we have further three sub-qualities, so a total of nine qualities.
So all individual Gopis with their individual but unique qualities, surrender to Krishna and wins His heart, and these sagun (good qualities) is then converted by Krishna into Nirguna nature (the duality of qualities disappear).
In the eleventh chapter of Shreemad Bhagvatam, Shree Krishna when speaking to Udhav (His close friend & His minister) explained the different qualities, the characters of His followers, are when surrendered to Him, gains in depth access inside Him “Anything that penetrates into me via total surrender will be automatically converted into ultimate form of Nirguna”.