The first is mindfulness of an object, any object. The second is mindfulness of the field of experience or “choiceless awareness”.
Kokyo Henkle: https://kokyohenkel.weebly.comThere is a third type of meditation, which I propose is the hallmark of traditional Zen. The Zen ancestors of China and Japan usually taught a zazen we could call awareness of awareness, or just being awareness itself. Awareness that is usually directed toward an object of experience, either a specific single object or the whole field of objects, is instead directed back upon itself, where it is always already shining. Since awareness itself is the only thing that is not an object of awareness, this is the end of subject-object duality, the cessation of the division of mind and experience. This is mindfulness of no object, nondual awareness, and when immersed in it, this is therefore the cessation of suffering, the end of discontent and grasping and fear, and the source of true love and compassion.
https://kokyohenkel.weebly.com/uploads/ ... _zazen.pdf