The primary industry refers to industries that provide means of production, including planting, forestry, animal husbandry, aquaculture and other production departments that directly target natural objects. Although some of them are industries, they are not processing industries. For example, the mining industry directly provides minerals but does not process them, so the mining industry belongs to the primary industry. The secondary industry refers to the processing industry that uses basic means of production to process and sell. The tertiary industry, also known as the service industry, refers to other industries other than the primary and secondary industries. The tertiary industry is extensive. Including transportation, communications, commerce, catering, finance and insurance, administration, family services and other intangible production sectors. The industrial division of different countries is not completely consistent. The usual three major industries are the classification methods used by the United Nations: the first industry includes agriculture, forestry, animal husbandry and fishery; The secondary industry includes manufacturing, mining, construction and public works, sewage, gas and health departments; The tertiary industry includes non-material production departments such as commerce, finance, insurance, real estate, transportation, communication and service industry.