A corporation is an organization—usually a group of people or a company—authorized by the state to act as a single entity (a legal entity recognized by private and public law "born out of statute"; a legal person in legal context) and recognized as such in law for certain purposes.^: 10 Early incorporated entities were established by charter (i.e., by an ad hoc act granted by a monarch or passed by a parliament or legislature). Most jurisdictions now allow the creation of new corporations through registration. Corporations come in many different types but are usually divided by the law of the jurisdiction where they are chartered based on two aspects: by whether they can issue stock, or by whether they are formed to make a profit. Depending on the number of owners, a corporation can be classified as aggregate (the subject of this article) or sole (a legal entity consisting of a single incorporated office occupied by a single natural person).

One of the attractive early advantages business corporations offered to their investors, compared to earlier business entities like sole proprietorships and joint partnerships, was limited liability. Limited liability means that a passive shareholder in a corporation will not be personally liable either for contractually agreed obligations of the corporation, or for torts (involuntary harms) committed by the corporation against a third party. Limited liability in contract is uncontroversial because the parties to the contract could have agreed to it and could agree to waive it by contract. However, limited liability in tort remains controversial because third parties do not agree to waive the right to pursue shareholders. There is significant evidence that limited liability in tort may lead to excessive corporate risk taking and more harm by corporations to third parties.

Where local law distinguishes corporations by their ability to issue stock, corporations allowed to do so are referred to as stock corporations; one type of investment in the corporation is through stock, and owners of stock are referred to as stockholders or shareholders. Corporations not allowed to issue stock are referred to as non-stock corporations; i.e. those who are considered the owners of a non-stock corporation are persons (or other entities) who have obtained membership in the corporation and are referred to as a member of the corporation. Corporations chartered in regions where they are distinguished by whether they are allowed to be for-profit are referred to as for-profit and not-for-profit corporations, respectively.

There is some overlap between stock/non-stock and for-profit/not-for-profit in that not-for-profit corporations are nearly always non-stock as well. A for-profit corporation is almost always a stock corporation, but some for-profit corporations may choose to be non-stock. To simplify the explanation, whenever "stockholder" or "shareholder" is used in the rest of this article to refer to a stock corporation, it is presumed to mean the same as "member" for a non-profit corporation or for a profit, non-stock corporation. Registered corporations have legal personality recognized by local authorities and their shares are owned by shareholders whose liability is generally limited to their investment.

Shareholders do not typically actively manage a corporation; shareholders instead elect or appoint a board of directors to control the corporation in a fiduciary capacity. In most circumstances, a shareholder may also serve as a director or officer of a corporation. Countries with co-determination employ the practice of workers of an enterprise having the right to vote for representatives on the board of directors in a company.

In American English, the word corporation is most often used to describe large business corporations. In British English and in the Commonwealth countries, the term company is more widely used to describe the same sort of entity while the word corporation encompasses all incorporated entities. In American English, the word company can include entities such as partnerships that would not be referred to as companies in British English as they are not a separate legal entity. Late in the 19th century, a new form of the company having the limited liability protections of a corporation, and the more favorable tax treatment of either a sole proprietorship or partnership was developed. While not a corporation, this new type of entity became very attractive as an alternative for corporations not needing to issue stock. In Germany, the organization was referred to as Gesellschaft mit beschränkter Haftung or GmbH. In the last quarter of the 20th century, this new form of non-corporate organization became available in the United States and other countries, and was known as the limited liability company or LLC. Since the GmbH and LLC forms of organization are technically not corporations (even though they have many of the same features), they will not be discussed in this article.