How are the words season, equinox and solstice related?

The equinox is when the Earth's day and night cycles are almost exactly the same, and happens twice a year.

The solstices are also twice a year, but are when the day/night cycle is at the most extreme because the earth's tilt is so pronounced. For example, the Summer solstice is the longest day of the year in the Northern hemisphere and

the shortest in the Southern hemisphere.

The time between the equinoxes and solstices is known as the seasons.