The word yoga means "to join". Although we are naturally part and parcel of the supreme, in our conditioned state we are now separated. Because of our separation, we are reluctant to understand God and to speak of our relationship with him and are even inclined to think of such discussion as a waste of time. In a mosque or church, we speak of God but people in general are not very interested. They think it's a waste of time, a kind of recreation in the name of spiritual advancement, and they believe that this time could be better used to earn money or enjoy themselves in a nightclub or restaurant.
Therefore, it is due to this sense enjoyment that we are not attracted to God, and therefore it is said that those who are addicted to sense enjoyment may not become yogis: that is, they are not eligible to practice in the yoga system. one cannot advance in any yoga system if it takes in sense gratification and then sits down to try to meditate. This is just a colossal hoax. Such contradictory activities has no meaning. First of all yoga means controlling the sense yama-niyama.
There are eight stages of yoga: yama, niyama, Asana, dhyāna, dhāranā, prānāyāma, pratyāhāra and samadhi.
Yes we have eight stages of yoga