A merger is a transaction in which two separate companies combine to form a new company, with the two constituent companies dissolved or becoming wholly-owned subsidiaries of the new combined parent company. The two constituent companies in a merger are usually considered equal partners. Conversely, an acquisition is a transaction in which one company takes over another company, either by acquiring ownership of the company, a controlling stake in the company, or all or substantially all of the assets of the acquired company. The acquired company then either becomes a wholly-owned subsidiary of the acquiring company or is dissolved with the acquiring company left remaining.