Two-point tensor

A two-point tensor, often referred to as a second-order tensor, is a mathematical object that can be represented as a rectangular array of numbers arranged in a 2-dimensional grid. In the context of physics and engineering, tensors are used to describe physical quantities that have multiple components and can occur in various coordinate systems. A two-point tensor typically has two indices, which can be thought of as pairs of values that represent how the tensor transforms under changes in coordinate systems.