A company is called a firm when it is a partnership of two or more persons. An organisation is an organized group of people with a particular purpose, such as a business or government department. Corporation is a large company or group of companies authorized to act as a single entity and recognized as such in law. An organisation can be a part of a corporation.
The only difference comes in Industry which generally denotes a group of companies connected with the manufacture and assembly of an automobile like car, Truck, bus, motorcycle etc. - Ex: Automobile industry will indicate a group of companies connected in some way to the making of an automobile. ( Like parts of engines, carburetors, etc.
A company is any form of business whether it is small or large. Generally the term "company" indicates a particular kind of business dealing in a specific product.
An organisation is the larger form and generally comprises of a number of companies. Simply, a company is an organization, but an organization is not just a company.
An industry is the combination of companies in same line of business.
Firm, corporation and business are synonyms of "company".
An Agency is a particular kind of company, which serves as an intermediary between clients (other companies or individuals).
The first thing that we are acknowledging is those concepts are different. Many variables enable to establish this. The legal statute, the neo classical and managerial definitions of firms and the objectives of organizations. The system theory enables to understand what is an institution.