An amalgamation is the combination of two or more related companies. The amalgamated entity may or may not be one of the original companies. The shareholders of each company become the shareholders of the amalgamated company, and the assets and liabilities of the merged companies are vested in the amalgamated company.
A merger is the formation of a new company from two or more existing companies, through pooling of common stock, cash payment or a combination of both. The companies being merged cease to exist and the shareholders of those companies become the shareholders of the new company.