Mesh analysis
[1] Mesh analysis/Mesh current method is a circuit analysis way to planar circuits. A general way called loop analysis (with the corresponding network variables called loop currents) is applied to any circuit (planar or not).
[2] Planar circuits are drawn on a plane surface without wires crossing each other.
Mesh analysis and loop analysis both use Kirchhoff’s voltage law (KVL) to get an equation set solvable if a circuit has a solution. Akin, nodal analysis is a systematic application of Kirchhoff's current law (KCL). It's often easier to use for planar circuits, like loop analysis.
planar: