A C corporation is a form of corporation that meets the U.S. IRS requirements to be taxed under Subchapter C of the Internal Revenue Code. It is also known as "C corporation" or "C-Corp". Most major companies are incorporated under a C corporation. After the corporation is created it becomes its own entity and has an indefinite lifespan as long as the yearly filing fee is paid.
C corporation vs. S corporation
The main differences between S corporation and C lie in the fact that a C corporation is taxed a Federal Corporate Income tax whereas an S corporation is not. It may also have an unlimited amount of shareholders unlike S corporations, which are limited to 100 shareholders.