Eggplant is not a type of squash. Eggplant is part of the potato family, and it has a peak season of August and September.
Eggplant range in color from deep purple to white. The white eggplant was the first to be discovered, and it is smaller than the purple variety most people know today. White eggplants are only available seasonally and have a firmer skin that must be peeled before cooking.
The purple eggplant is available year-round, and it is often bitter until cooked. Purple eggplant is popular in a number of cultures, and it has a variety of names, including aubergine, garden egg and patlican.