Earth's Rotation

As the earth revolves around the sun it is spinning or rotating like a top.
It spins around an imaginary line called its axis.  The earth makes one
complete rotation in 23 hours and 56 minutes.

Earth's Revolution

Earth revolves once around the sun in about 365 days (one year.)
The path it follows is known as its orbit. During its elliptical orbit, its
distance from the sun changes.  The closest point is earth's
perihelion.  The farthest point is its aphelion.

Seasons

Because of the tilt of the earth's axis (23.5°), the amount of sunlight
falling on a region of the earth changes throughout the year.
 

Solstices and Equinoxes

zenith - highest point in the sky, directly overhead
solstice - when the noon sun is directly overhead
equinox - when the noon sun is directly over the equator

(See web lesson) http://vortex.plymouth.edu/sun.html or http://vortex.plymouth.edu/sun/sun.html