The resources used in production are called factors of production. These are the resources required to produce goods and services. The three main factors of production are land, labor, and capital. Land refers to natural resources such as land, water, and minerals, while labor refers to the work done by people to produce goods and services. Capital refers to the tools, equipment, and other resources used in the production process. The combination of these factors of production determines the quantity and quality of the goods and services produced.