A corporation is a group of persons that sit together to make and run a business. This business is considered an entirely different human and not related to the group which manages it.
Because it is recognized by governments as a separate person entirely, the corporation must pay it's own taxes and conform to state and federal law. This difference of persons and corporation gives it special powers. A corporation's special powers are determined by the law of the country in which the corporation is set up.
Investors(people who own a small part of the company) and entrepreneurs(The people who founded the company and it's ideas) often form joint stock companies. Therefore, the term corporation often means such business corporations. Corporations may also be formed for local government (municipal corporation), political, religious, and charitable purposes (not-for-profit corporation), or government programs (government-owned corporation). Condominiums are a common kind of non-profit corporation.
In common speech, the word "corporation" refers usually to limited responsibility corporation. That is a business firm where each of the partners invest a sum of money in as the capital of the corporation. They receive shares for the sum they have invested. If the company becomes bankrupt, the business partners are responsible for only the name value of their shares of the company's debts. The partners do not use their personal money to pay for the debt.