Explain the difference between the first day of spring (vernal equinox) and the first day of summer

In the northern hemisphere when its the first day of spring, which is the Vernal Equinox. In the southern hemisphere that makes it fall, therefore fall equinox. The difference is they both are opposite seasons at the same time.

Explanation: Please give me a good rating this is the right answer :)

i feel as if they would both catch on before to long because they would see them to frequent