This posture is part of the asana practice of yoga. An asana is a form, or posture.

Warrior II (Virabhadrasana II) is a powerful form. Practicing this form can lead you to find strength, courage, and confidence.  To practice Warrior II flow follow the simple steps:

Inhale and stand tall, feet flat on the ground. Exhale and step your right foot back behind the other in a parallel plane to your front leg, turning the right toes perpendicular to the front foot. Bend the front (left) knee. Turn your torso in the direction of your back feet and raise your arms so that your left arm faces forward and your right arms faces behind you.

To integrate the flow:

Inhale, straighten the front leg and raise your arms above your head
Exhale, bend the front knee and bring your arms to the front and back

Feel your strength and courage as a peaceful warrior.