The legal process of forming a corporation by filing Articles of Incorporation with the state.
Incorporation is the act of legally creating a corporation. You file Articles of Incorporation with your state's Secretary of State (or the Delaware Division of Corporations for a Delaware company), pay the filing fee, and the corporation comes into existence. From that moment, the corporation is a separate legal person.
For startups, "incorporating" often specifically means forming a Delaware C-Corporation because that's the standard for venture-backed companies. The actual filing can be done in a day through services like Stripe Atlas or Clerky, or directly through Delaware's online filing system.
After incorporating, several steps complete the setup: adopting bylaws, holding an organizational board meeting, issuing founder shares, adopting a stock option plan, and having founders sign PIIA agreements. Incorporation is just the first step — the legal setup isn't complete until these follow-on actions are done.