net, mesh fabric, known from prehistoric times. Nets have been made of many materials, including sinews, strips of hide, silk, vegetable and synthetic fibers, and metallic threads. Their earliest use was probably for snaring animals and for fishing. Fishing nets include the stationary net, an early type; the drift net, an oblong vertical net, buoyed on its upper edge; the seine, whose ends are brought together to enclose the fish; and the bag-shaped trawl net, dragged along sea bottom. Hair nets include the gold or silver, wire or cord cauls worn in ancient Egypt, Greece, and Rome; reticulated caps and cauls popular in Europe especially in the 14th cent.; chenille or ribbon snoods of the 19th cent.; and the "invisible" net of human hair. Net fabrics include veilings, tulle, and maline, as well as heavier dress nets, curtain nets, and filet, a foundation for lace. Nettings are used also for safety nets, for hammocks, and for hoisting loads.

Type of parallel computation in which computing elements are modeled on the network of neurons that constitute animal nervous systems. This model, intended to simulate the way the brain processes information, enables the computer to “learn” to a certain degree. A neural network typically consists of a number of interconnected processors, or nodes. Each handles a designated sphere of knowledge, and has several inputs and one output to the network. Based on the inputs it gets, a node can “learn” about the relationships between sets of data, sometimes using the principles of fuzzy logic. For example, a backgammon program can store and grade results from moves in a game; in the next game, it can play a move based on its stored result and can regrade the stored result if the move is unsuccessful. Neural networks have been used in pattern recognition, speech analysis, oil exploration, weather prediction, and the modeling of thinking and consciousness.

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System by which employees are paid a share of the profits of the business enterprise in which they are employed, in keeping with a plan outlined in advance. These payments, which may vary according to salary or wage, are in addition to regular earnings. Profit-sharing plans were probably first developed in France in the early 19th century as worker incentives. Today such plans are used by businesses in Western Europe, the U.S., and parts of Latin America. Profit shares may be distributed on a current or deferred basis or through some combination of the two. Under current distribution, profits are paid out to employees immediately in the form of cash or company stock. In deferred-payment plans, profit shares may be paid into a trust fund from which employees can draw annuities in later years.

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In business usage, the excess of total revenue over total cost during a specific period of time. In economics, profit is the excess over the returns to capital, land, and labour. Since these resources are measured by their opportunity costs, economic profit can be negative. There are various sources of profit: an innovator who introduces a new production technique can earn entrepreneurial profits; changes in consumer tastes may bring some firms windfall profits; or a firm may restrict output to prevent prices from falling to the level of costs (monopoly profit).

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