logical standards of the network in creating new types of services. A company that owns a network can in principle grant selective platform access to a select group of companies through licenses, partnerships, and other contracts. Alternatively, a network owner can open its network services and standards to any company that provides complementary goods and services. A network is said to be modular or to exhibit an open architecture if most suppliers of complementary services can gain access to the network. The Internet is the prime example of open architecture. The transfer control protocol and Internet protocol (TCP/IP) are open standards that allow a wide variety of software applications to be transmitted over the Internet, permitting such services as search engines and Internet commerce to be provided by companies using the Internet. In addition, a wide variety of types of information including voice, data, images, and video can be transmitted over the network. Discussions of networks often include other industries in which companies sell complementary goods, such as cameras and film. When standards are widely available and not necessarily proprietary, independent companies can produce complementary components, allowing consumers to assemble groups of products. The Structure and Functions of Networks In information technology, the IBM standard made possible a modular set of products that are complementary SO that consumers can obtain computers, soft- ware applications, and peripheral devices such as printers, monitors, and memory devices that work together. In addition, the components of the computer itself, including microprocessors, memory chips, and monitors, are sufficiently standard- ized to allow these products to be supplied by a variety of industries connected to information technology. Such common technological standards need not be con- fined to high technology, because similar modularity is observed in a variety of products such as automobiles, bicycles, audio systems, and video display systems. Mul