From HomoExcelsior

1. A closed path followed or capable of being followed by an electric current. 2. A configuration of electrically or electromagnetically connected components or devices.

In computer science and mathematics a circuit has another specific meaning in graph theory. A circuit within a graph is a set of edges which is contiguous. A circuit may contain sub-circuits, and a graphic may not contain any circuits. See also: Hamilton circuit, Euler circuit.

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