  Complexiton solutions (or complexitons for short) are exact solutions newly
introduced to integrable equations. Starting with the solution classification
for a linear differential equation, the Korteweg-de Vries equation and the Toda
lattice equation are considered as examples to exhibit complexiton structures
of nonlinear integrable equations. The crucial step in the solution process is
to apply the Wronskian and Casoratian techniques for Hirota's bilinear
equations. Correspondence between complexitons of the Korteweg-de Vries
equation and complexitons of the Toda lattice equation is provided.
