A C corporation is the standard corporate structure and is a separate legal entity from its owners. It may have an unlimited number of shareholders, generally provides limited liability protection to its shareholders, and is commonly used by companies seeking outside investment or venture capital funding.

An S corporation is generally a corporation or eligible LLC that has elected S corporation tax treatment with the IRS and, where required, the applicable state tax agency. It provides pass-through taxation to shareholders but is subject to ownership, shareholder, and stock class restrictions.

A limited liability company, or LLC, is a flexible business structure that generally provides limited liability protection to its owners, known as members. An LLC may be taxed as a disregarded entity, partnership, C corporation, or S corporation, depending on its ownership and tax elections.

A nonprofit corporation is formed for purposes other than distributing profits to owners or shareholders. Nonprofit corporations are commonly used for charitable, religious, educational, scientific, civic, or similar purposes and may apply for tax-exempt status if eligible.