In the 1500's there occurred something called the columbian exchange what was it why was it important give me two examples?

The columbian exchange was important in the history of the world because it promoted the exchange of idea's and item between continents and changed lives in Europe, Asia, Africa, and the Americas.

Examples are :

New World to Old World: tomatoes, potatoes , squash, beans, pumpkins, tobacco, corn and even chocolate.

Old World to new World: cows, pigs, goats, horses, chickens, citrus fruits, grapes and onions and even smallpox.