Mergers and acquisitions involve the combination of two or more companies. A merger combines two approximately equal-sized companies, while an acquisition sees one larger company purchase a smaller one. There are several types of mergers, including horizontal (between competitors), vertical (between companies in a supply chain), and conglomerate (between unrelated industries). Reasons for mergers and acquisitions include gaining synergies between companies, removing unprofitable business lines, focusing on core competencies, generating cash, withstanding competition, and facilitating further growth.