A network, in the context of electronics, is a collection of interconnected components. Network analysis is the process of finding the voltages across, and currents across, every component in the network. There are many different techniques for calculating these values. However, for the most part, the applied technique assumes that the components of the network are all linear. The methods described in this article apply only to linear network analysis, except where explicitly stated.
A useful procedure in network analysis is to simplify the network by reducing the number of components. This can be done by replacing the actual components with other notional components that have the same effect. A particular technique could directly reduce the number of components, for example by combining impedances in series. On the other hand, you could simply change the shape into one in which the components can be reduced in a later operation. For example, a voltage generator could be transformed into a current generator using Norton's theorem to be able to later combine the internal resistance of the generator with a parallel impedance load.
A resistive circuit is a circuit that contains only resistors, ideal current sources, and ideal voltage sources. If the sources are constant sources (DC), the result is a DC circuit. The analysis of a circuit consists of solving the voltages and currents present in the circuit. The solution principles described here also apply to phasor analysis of AC circuits.