I've heard about it, but… 12- What is peanut butter?

Peanut butter is a food paste made primarily from ground dry roasted peanuts, popular in North America, Netherlands, United Kingdom, and parts of Asia, particularly the Philippines and Indonesia. It is mainly used as a sandwich spread, sometimes in combination with other spreads such as in the peanut butter and jelly sandwich. The United States and China are leading exporters of peanut butter. Other nuts are used as the basis for similar nut butters.

Peanuts are native to the tropics of the Americas and were mashed to become a pasty substance by the Aztec Native Americans hundreds of years ago.[2] A number of peanut paste products have been used over the centuries, and the distinction between peanut paste and peanut butter is not always clear in ordinary use. Early forms of peanut butter, like the Aztecs' version, were nothing but a paste made from roasted peanuts. Modern processing machines allow for very smooth products to be made, which often include vegetable oils to aid in its spreadability.

Peanut butter is a source of incomplete protein. A common combination to provide a complete protein is pairing peanut butter with whole wheat bread, however, the two foods need only be consumed within 24 hours of each other to complete the protein.