Garuda Purana talks about 84 lakh Yonis(species).

All of them are categorised into four types:
• उद्भिज्ज (born out of earth)
• स्वेदज (born out of sweat)
• अण्डज (born out of egg)
• जरायुज (born out of womb)

Further, it talks about how a soul takes birth into different Yonis.

The path goes from top to bottom: उद्भिज्ज -> स्वेदज -> अण्डज -> जरायुज

Out of all four, जरायुज योनि is considered the best. Inside जरायुज, a human birth is considered the best.

When a जीव gets human birth, it starts from the very bottom and goes higher(based on karmic debt, whether good or bad).

Sometimes, the जीव skips some steps in between because of some पुण्य and directly attains a higher birth.

Lets talk about a birth inside Human योनि‌ now.

The purana says, that a जीव can become कुत्सित, वामन, चाण्डाल, etc., to experience the fruits of karmas.

When the debt becomes lighter, he touches the four Varnas(ब्राह्मण, क्षत्रिय, वैश्य, शूद्र).