Two general approaches to network analysis

 (i) Direct Method Here, the network is left in its original form while determining its different voltages and currents. Such methods are usually restricted to fairly simple circuits and include Kirchhoff’s laws, Loop analysis, Nodal analysis, superposition theorem, Compensation theorem and Reciprocity theorem etc. 

(ii) Network Reduction Method Here, the original network is converted into a much simpler equivalent circuit for rapid calculation of different quantities. This method can be applied to simple as well as complicated networks. Examples of this method are : Delta/Star and Star/Delta conversions. Thevenin’s theorem and Norton’s Theorem etc.