Is An Equinox The Same As A Solstice?

Not at all. Equinox as implied in the spelling is a day when the hours of darkness and daylight are equal. It occurs twice in any one calendar year, March 21st and September 21st. In the northern hemisphere March 21st is known as the Vernal Equinox and September 21st as the Autumnal Equinox but the terms are reversed in the southern hemisphere.
A solstice also occurs twice a year – once on December 21st when the hours of daylight are shortest, this is known as the Winter Solstice – and once in midsummer when we enjoy the longest period of daylight. This is on June 21st, called midsummer's day in Britain. Those following more ancient pagan beliefs sometimes place this as June 24th.
The terms as mentioned earlier are reversed in the southern hemisphere.
The effect is cause by the tilt in the axis of the earth which shows and apparent movement of the sun between the tropic of Capricorn and the tropic of Cancer. It is in reality the Earth's orbit in conjunction with the axis which gives rise to this.