Primary Industry – A business that extracts the earths natural resources

To remember what primary industry is use the following mnemonic:

The primary school was in the mining industry (primary industry). It's run like a business that extracts the earth's natural resources.

Another way of remembering the meaning of primary industry is to recall that:

Primary = earliest in time/order.

and 

Industry = companies and activities involved in the process of producing goods for sale.

Primary Industry – A company whose activities are the earliest in the process of producing goods for sale, which is extracting natural resources

Examples of primary industries include mining, farming, fishing and forestry (logging). These are all at the beginning of their respective manufacturing processes to make goods. For example, the first stage in producing the paper you write on was a logging company cutting down the trees to be transported to the processing plant.

The percentage of the population of a country who work in primary industries decreases as the economies of the country grows. For example, agriculture, forestry and fishing comprises more than 15% of gross domestic product (a country's total economic output) in sub-Saharan African nations, but less than 1% of GDP in North America.