Posture is the physical foundation of meditation practice. The essential requirements are stability and alertness — you want to be comfortable enough to sit still but not so relaxed that you fall asleep. Common positions include: full lotus (both feet on opposite thighs), half lotus (one foot on the opposite thigh), Burmese position (both feet on the floor in front), kneeling on a meditation bench, or sitting upright in a chair with feet flat on the floor. The spine should be upright but not rigid, the hands resting in the lap or on the knees, the chin slightly tucked, and the gaze soft or the eyes closed. No single posture is correct — the right posture is the one that keeps you alert and stable.

Reference:

Wikipedia: Meditation Postures

https://en.wikipedia.org/wiki/Meditation