Articles of incorporation and articles of organization are often confused, but the difference is straightforward: one forms a corporation, the other forms an LLC. Which you file depends entirely on which entity type you're actually creating.
Articles of incorporation form a corporation
Filed with the state to create a C-corp or S-corp, articles of incorporation typically establish the corporate name, registered agent, number of authorized shares, and incorporator information — the foundational document a corporation's bylaws and share structure build on top of.
Articles of organization form an LLC
The equivalent document for an LLC, articles of organization establish the LLC's name, registered agent, and management structure (member-managed or manager-managed) — with the operating agreement, not the articles themselves, governing the actual internal rules.
Some states use different names for the same concept
Texas, for instance, calls its LLC formation document a Certificate of Formation rather than Articles of Organization — functionally the same document, different terminology. Worth confirming your state's specific naming before searching for the wrong form.
Neither document alone fully protects you
Both are just the starting point — the bylaws (for a corporation) or operating agreement (for an LLC) are what actually govern day-to-day decisions, ownership changes, and disputes, and skipping them is one of the most common gaps in new business formations.