"How can a constellation have one or two points?"

The difference between one and two is the degree. For example, a circle has 360 degrees. For the convenience of astrology, people regard the ecliptic plane as a circular orbit divided into 12 equal parts. 360 degrees divided by 12 constellation, each constellation accounts for 30 degrees. Each constellation is divided into equal parts again and again. Taurus I, Taurus II and Taurus III have different degrees. Different degrees of division can better predict the horoscope.