What does calligraphy theory mean?

Linghou is a Chinese character, which refers to calligraphy terms. The ups and downs in writing and writing.

Press, it is a pen to go down; Lift the pen, that is, lift the pen up. If you lift it, the pen can keep the nib in the center.

He Jiang in the Qing Dynasty said, "You must mention it after meals and after staying overnight. When the pen holder raises the pen, it will be reduced to beard score and squat score.