While the fields of knowledge are divided into the four types mentioned above, the field of Yoga may be classified into three main categories:
(1) Karma Yoga, which places particular emphasis on action.
(2) Karma Yoga blended with devotion.
(3) Karma Yoga dominated by devotion.
(1) Karma Yoga, which places particular emphasis on action, is the fulfillment of duties prescribed in the scriptures, taking into full consideration the social context and the stage of life, and involves completely abandoning the desire for the fruits of all actions and attachments to worldly things. In the teachings related to this type of Karma Yoga, the Lord has, in some places, advocated for the abandonment of only the fruits (V.12; VI.1; XII.11; XVIII.11); in other places, He has emphasized only the abandonment of attachment (III.19; VI.4). In still other places, He has demanded the abandonment of both fruits and attachment (I.47, 48; XVII.6, 9). When emphasis is placed only on the abandonment of fruits, it should be considered that the abandonment of attachment is also covered. In contexts where only the abandonment of attachment is emphasized, the abandonment of fruits should also be understood as implied. Disciplined action can only be truly realized when both fruits and attachments are abandoned.
(2) Karma Yoga integrated with devotion: In this field, practitioners were asked to consider God as present in the entire universe, and to worship Him through the performance of duties appropriate to their varna (social class) (XVIII.46).
(3) Selfless action as the dominant Karma Yoga: This can be further divided into:
(a) Offering actions to God.
(b) Performing actions for God.
The actions offered to God are also practiced in two ways. One is known as "complete surrender," in which the devotee abandons, in all actions, the sense of "I," attachment, and the desire for fruits. He believes that everything belongs to God, that he himself belongs to God, and that every action performed by him is God; just as an actor accomplishes everything through his character, everything is accomplished by God. And with this belief, he performs the duties prescribed in the scriptures (Sāstras) according to his will and only for his pleasure (III.30; XII.6; XVIII.57,66).
In addition to this, actions initially performed for reasons other than God may later be offered to God. These offerings may occur during the process of the activity, or even in the midst of its execution. They may also be offered immediately after completion, or only the fruits of the action may be offered. All of these are preliminary stages, and represent many ways in which one can offer one's actions to God. Ultimately, reaching the stage of "complete surrender" is achieved through the continuous practice of these preliminary stages.