Meridians-human meridians include meridians and collaterals. Meridian, like a straight path, is the backbone of the meridian system. Collaterals have the meaning of network and are tiny branches of meridians. Meridians belong to the five internal organs and external collaterals, which promote the circulation of qi and blood, communicate yin and yang, and communicate inside and outside. The network is all over the body, connecting all parts of the human body into a unified whole to maintain the coordination and balance of its functional activities. Acupoints-points distributed on meridians. Generally speaking, meridians are like subway lines, and acupoints are like stations on various lines.