In this unit, you have learned about methods of network analysis which are general in nature such as KCL, KVL, Nodal and Mesh analysis. These general methods may be used for any network and enables us to determine current and voltages in all of branches of the network. Though in some network problems it is needed only restricted analysis such as to determine the current, voltage and power in a load resistance across given two terminals of a network. For such limited analysis the desired results can be obtained more conveniently using certain network theorems. In this unit, you have treated with some of the significant network theorems like Thevenin's and Norton's theorem.
Here you have also study source transformation techniques.