Where the Ecliptic and the Earth's Celestial Equator cross, is called
an Equinox, for 'equal'. There are two: vernal and autumnal.
The other two points of interest are the Solstices, where the Ecliptic and
Celestial Equator are most distant, having a winter and summer solstice.
Note that when the Sun lies in the direction of the Summer Solstice, rotation of the earth will not make the Sun set in the North Pole! Likewise, from the North Pole, when the Sun is at the Winter Solstice, the Sun will always be below the horizon. When the Sun is at either of the Equinoxes, The Sun stays right on the horizon.
With a little bit of thought, you can imagine how this effects our view of the Sun from Cincinnati: at Summer Solstice, the Sun is much higher in the sky during the day and also stays above the horizon longer. This explains the Seasons we see on earth.
