This document defines key concepts related to business and industry. It explains that business involves the purchase, production and sale of goods and services with the aim of earning profits. Economic activities are those performed to earn a livelihood through the production of goods and services, while non-economic activities are performed for psychological satisfaction. Industries are divided into primary, secondary and tertiary. Primary industries involve extraction and agriculture. Secondary industries process primary goods and manufacture finished products. Tertiary industries provide services to other industries and facilitate trade. Commerce aims to facilitate the exchange of goods and involves both trade and auxiliary activities that support trade.