There are many different kinds of yogis. Yoga means the system, and the yogi means the person who practices the system. So the object of yoga, ultimate goal of yoga, is to understand Kṛṣṇa. Therefore Kṛṣṇa consciousness means to practice the topmost type of yoga system. So this yoga system is being described by Kṛṣṇa Himself. Why? Because He was teaching His most intimate friend, Arjuna. (Sanskrit commentary) Vyākhyāta-lakṣaṇe svopasye mayy āsakta-mati-mātra nitaraṁ mano yasya saḥ. Now in the beginning, the Lord says that "This system of yoga can be practiced by persons who have developed attachment for Me." This attachment I have described for the last three, four days, in a different way. So this yoga system cannot be practiced by an ordinary man who has no attachment for Kṛṣṇa. This is a different system. And the topmost. (Sanskrit commentary) Tvam anyo vā tadṛṣo mad-āśrayo mad-dāsya-sakhyādy-ekatamena bhāvena.
There are five kinds of direct āsakti. Āsakti means attachment. And there are seven kinds of indirect attachment. Indirect attachment is not bhakti, but direct attachment is called bhakti. If you are attached to Kṛṣṇa by the direct method, it is called devotional service. And if you are attached to Kṛṣṇa by indirect method, then it is not devotional service. But that is also attachment. Just like Kaṁsa. Kaṁsa was the maternal uncle of Kṛṣṇa, and there was a foretelling that Kaṁsa would be killed by his sister's son, eighth son of his sister. So Kaṁsa became very anxious and he wanted to kill his younger sister, Devakī, Kṛṣṇa's mother. So she was saved by her husband, Kṛṣṇa's father, Vasudeva, by some compromise. The last compromise was... That's a great long story. The last compromise was that he informed his brother-in-law Kaṁsa that "You are afraid of the son of your sister. So your sister is not going to kill you. So I request, don't kill your sister. Save her. And I promise that all the sons born of your sister will be brought to you, and if you like, you can kill." The compromise was made by Vasudeva. He was also a king.
So politically, that "For the time being this poor girl may be saved, and it may be that time will change the mind of Kaṁsa. When her sons will be born he might change his mind." But he was such a great demon that he killed all the sons of Devakī. So the eighth son... It was foretold that the eighth son of his sister would kill him. So when Kṛṣṇa was in the womb of his mother, Kaṁsa was always thinking of Kṛṣṇa. Now you see, he was also Kṛṣṇa conscious, but he was Kṛṣṇa conscious not directly, not for love's sake, but as an enemy. He was Kṛṣṇa conscious as enemy. So that is not devotional service. One who is Kṛṣṇa conscious and Kṛṣṇa's friend, Kṛṣṇa's parent, Kṛṣṇa's servant, Kṛṣṇa's lover, that is devotion.