What happens during the June 21 summer solstice

The video explains how Earth rotates on a tilted axis while orbiting the sun, causing different parts of the planet to point towards or away from the sun at different times of the year. During the June 21 solstice, the North Pole tilts towards the sun, resulting in the sun shining directly overhead at the Tropic of Cancer. This causes minimal shadows and marks the longest day and start of summer in the Northern Hemisphere, while the Southern Hemisphere experiences the shortest day and the start of winter.

What is the significance of the sun being directly overhead at noon on the Tropic of Cancer?

Explain the difference in day length experienced by the northern and southern hemispheres during the solstice.