The word Chocolate comes from the Aztec word "xocolatl" meaning "bitter water".  Is the edible product of the tropical cocoa bean, Theobroma cacao (means "food of the gods"). Cacao played important role in Mayan, Toltec, and Aztec culture-beans used both as food and form of payment
Some scholars say Columbus brought cacao beans back to Spain, it wasn't until Hernan Cortes returned to Spain in 1527 or 1528 with usage tips from the Aztecs (as in how to mix it with other ingredients to make a beverage that it found any real use in Europe.

Knowledge remained in Spain for about 100 years before spreading in Europe; moved into Africa around 1822-currently the largest cacao producing countries are in Africa (larger quantities, for industrial uses) and South America (higher quality) originally consumed in the form of a beverage; first chocolate "bar" in 1847 in England                                                                                                                                             
Different types available include: unsweetened, bittersweet, dark, milk, and white; also cocoa products such as cocoa powder