What is a conglomerate? (like business not rocks)

Large corporation run as a single business, but made up of several firms (acquired through mergers or takeovers) supplying diverse goods and/or services. Berkshire Hathaway Inc. is one of the biggest conglomerates in the world, with ownership of insurance, utilities, financial, and retail companies

A conglomerate is the combination of two or more corporations operating in entirely different industries under one corporate group, usually involving a parent company and many subsidiaries. Often, a conglomerate is a multi-industry company. Conglomerates are often large and multinational.