\nablaThe nabla symbol (∇) is used in vector calculus to denote the gradient, divergence, or curl of a field. It is a vector differential operator represented by the symbol ∇ and is used to calculate the gradient of a scalar field, the divergence of a vector field, or the curl of a vector field.
Gradient of a scalar field f(x, y, z)
\nabla f(x, y, z)Divergence of a vector field F
\nabla \cdot \mathbf{F}Curl of a vector field F
\nabla \times \mathbf{F}