Abstract
Complexiton solutions (or complexitons for short) are exact solutions newly introduced to integrable equations are newly introduced. 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.