An industry is a classification that refers to groups of companies that are related based on their primary business activities. In modern economies, there are dozens of industry classifications, which are typically grouped into larger categories called sectors,

Industry is the production of goods or related services within an economy. The major source of revenue of a group or company is the indicator of its relevant industry. When a large group has multiple sources of revenue generation, it is considered to be working in different industries.
What is an industry