Polyculture is the practice of growing multiple crops in one specific area of land, while monoculture means that an area of land only grows a single crop. A garden is an example of polyculture, and a cornfield is an example of monoculture.
Most early farming was monoculture. Although it produces an abundance of a particular crop, there are some disadvantages to monoculture. A farmer needs a large amount of land for each type of crop as well as a complex irrigation system.
Polyculture, by contrast, means all the crops are in one place, so less land and water are needed. It also produces higher crop yields.