What is winter solstice?

On 22^nd December, the tropic of Capricorn receives direct rays of the sun as the South Pole tilts towards it .As the sun’s rays fall vertically at the tropic of Capricorn

(231/2 ^os), a larger portion of the southern. Hemisphere gets light. Therefore, it is summer in the southern Hemisphere with longer days & shorter nights. The reverse happens in the Northern Hemisphere. Thus posible of the earth is called the winter solstice.