In handstand you begin with a half version of the pose. It helps you to gain strength, confidence and familiarity with being upside down. Eventually you work with the action of kicking into the full inversion. You then explore the techniques of the final pose.
Headstand is presented in a similar way. Preparatory stages that build strength and technical understanding are undertaken first. You then learn ways of using props to support your neck when you begin coming closer to the full inversion. Eventually you are guided through the techniques of the final position.
Key Poses: Sirsasana, adho mukha vrksasana