In a general sense, holding companies are conglomerates that own other firms. offers a more specific definition: "A company that owns enough voting stock in another firm to control management and operations by influencing or electing its board of directors. Also called parent company."

A good example is Warren Buffett's Berkshire Hathaway (NYSE:BRK-A), which owns GEICO, See's Candies, Executive Jet, and Benjamin Moore paints, among many other businesses. Another major holding company is Fortune Brands (NYSE:FO), which is involved in home and hardware products (Moen, Aristokraft, Schrock, Diamond, Omega, Therma-Tru, Master Lock, and Waterloo), spirits and wine (Jim Beam, Knob Creek, DeKuyper, The Dalmore, Vox, Geyser Peak, and Wild Horse), golf equipment (Titleist, Cobra, and FootJoy), and office products (Swingline, Wilson Jones, Kensington, and Day-Timer).

Want more? Consider Tyco (NYSE:TYC), which encompasses the security company ADT, among many other businesses. Tyco is even the leading producer of acetaminophen (the active ingredient in Tylenol) in the world. Then there's United Technologies (NYSE:UTX), with its Pratt & Whitney aircraft division; Carrier heating, air conditioning, and refrigeration; Otis elevators and escalators; Sikorsky helicopters; International Fuel Cells power systems; and more. Get the picture?

While many companies routinely gobble up other companies, they frequently aim to blend these acquisitions into their operations. Holding companies keep the businesses they buy more separate.

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Tyco is a Motley Fool Inside Value selection.