Answer:

1. It's tilted about 23.5 degrees relative to our plane of orbit (the ecliptic) around the Sun. As we orbit our Sun, our axis always points to the same fixed location in space. Our northern axis points almost directly toward Polaris, the North Star. This picture shows Earth from its side as it orbits our Sun.

2. When the Northern Hemisphere is tilted toward the sun, latitudes between the equator and 90°N (the North Pole) are experiencing summer. At the same time, the Southern Hemisphere is tilted away from the sun and experiencing winter. ... Fall or autumn in the Northern Hemisphere begins September 22 or 23.

3. Whichever hemisphere (the Northern or Southern Hemisphere) is tilted toward the sun receives more direct rays of sunlight (or rays that are closer to perpendicular or a 90° angle). The hemisphere tilted toward the sun also has more hours of daylight than the hemisphere that is tilted away from the sun.

4. If the earth wasn't tilted on its axis, would that change the length of the day? The total length of the day wouldn't change unless you also had the Earth rotate at a different speed. However the amount of daylight would change and would become 12 hours, everywhere, all the time.

5. The effect of this variation is a variation in the length of the seasons – so that, at the maximum point of tilt, the areas receiving maximum/minimum daylight at the solstices are those north or south of 24.4⁰ latitude. The tilt of the earth doesn't just affect the amount of daylight reaching the earth's surface.