What is the meaning of solar terms and vernal equinox?

1. means "vernal equinox and autumnal equinox, divided equally between day and night".

On the vernal equinox, the sun shines directly at the equator, almost as long as the day and night in the world, that is, 12 hour. At this time, after half a year of darkness, the North Pole will first see the sun on this day, and the corresponding South Pole will also bid farewell to the sun on this day. After the vernal equinox, the position of the direct point of the sun will move northward, and the daytime time will be longer and the nighttime time will be shorter in the northern hemisphere. The difference is that the southern hemisphere will become shorter.

2. It refers to the equal division of four seasons.

If the period from the beginning of spring to the long summer is regarded as spring, the vernal equinox is the midpoint of spring, which just divides spring equally. It takes 90 days to travel from beginning of spring to Changchun, and the vernal equinox is divided into two, hence the name vernal equinox.