There are two independent fundamental differential operators (called the "fundamental differential operator pair") on curved surfaces. This paper focuses on the topic: Among all fundamental differential operator pairs, [[(Δ),(Δ)]], formed by the classical gradient (Δ) (··· ) and the shape gradient (Δ) (··· ), is the optimal one. The following conclusions are included: (1) The paths for constructing the fundamental differential operator pairs are not unique. (2) The commutative nature of the inner-product of [[(Δ), (Δ)]] is the basis of its optimality and advantage over all other fundamental differential operator pairs. (3) Based on the inner-product of [[(Δ), (Δ)]]l, all higher order scalar differential operators for physics and mechanics on curved surfaces can be constructed optimally. In other words, [[(Δ), (Δ)]] is the optimal "fundamental brick" for establishing the differential equations of physics and mechanics on curved surfaces. (4) [[(Δ), (Δ)]] exists universally in physics and mechanics on soft matter curved surfaces.%曲面物理和力学中有两个独立的基本微分算子(即“基本微分算子对”).本文综述如下主题:在所有的基本微分算子对中,经典梯度▽(…)和形状梯度(▽)(…)的配对[▽,(▽)]是最佳的.具体内容包括:(1)基本微分算子对的形式并不唯一;(2)内积的可交换性确立了[▽,(▽)]优于其他基本微分算子对的“最佳”地位；(3)基于[V,(▽)]可以最佳地构造曲面物理和力学的高阶标量微分算子,因而[▽,(▽)]是构造曲面物理和力学微分方程的最佳“基本砖块”；(4)[▽,(▽)]在软物质曲面物理和力学中普遍存在.
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