Resonance is a way to describe the electronic structure of molecules or ions that cannot be adequately represented by a single Lewis structure. In resonance structures, the position of electrons is shifted while the positions of atoms remain the same. The actual molecule is considered to be a hybrid of all the contributing resonance structures. Resonance is important for understanding the stability and reactivity of many organic compounds, including aromatic compounds and conjugated polymers.

共振是一种描述不能用单个路易斯结构充分表示的分子或离子的电子结构的方法。在共振结构中，电子的位置发生移动，而原子的位置保持不变。实际分子被认为是所有贡献共振结构的混合体。共振对于理解许多有机化合物（包括芳香族化合物和共轭聚合物）的稳定性和反应性很重要。