The type of law that regulates business industry and individuals is called Companies Law. This law covers almost every type of business, corporations and partnerships.
Administrative Law
an industry is a type of business, like the automobile industry. they make automobiles, or cars
partnership
A mining industry is a mining business or a type of job out of all the other jobs.
Corporation
Service industry
An industry is a type of business in the economy while a firm is a unit or entity carrying a portion of the business in an economy.
partnership
That depends on the type of business/industry involved.
The definition differ based on the industry. If you search for the article "Summary of Size Standards by Industry Sector" on the sba.gov website, you will find the exact definitions for the industry and type of business you're interested in.
partnership
Partnership