Farro is an ancient wheat grain originating from Mesopotamia.
There are three different types of grains commonly referred to as Farro.
Triticum monococcum - Einkorn: Farro piccolo (small)
Triticum dicoccum - Emmer: Farro medio (medium)
Triticum spelta - Spelt: Farro grande (large)
Obviously this results in a good bit of confusion because these names are used interchangeably depending on where you live.
What is commonly found in the US and Europe is Emmer wheat. It's sold dry and prepared by cooking it in water until it's soft and chewy. Dry grains look like wheat berries; once cooked it looks a lot like barley
Farro has a nutty flavor and chewy texture, and is a great alternative to buckwheat, barley, quinoa or rice.