Short Definition
A matrix is a rectangular array of numbers used to represent linear transformations, datasets, or model weights.
Intuition
Matrices let models transform many numbers at once, which is why they sit at the center of modern ML computation.
Technical Definition
A matrix is a two-dimensional array representing a linear map between vector spaces or a structured collection of values.
Example
A neural network layer multiplies an input vector by a weight matrix.
Common Misunderstandings
A matrix is not only a table; it can represent a transformation.
Matrix shape determines whether operations are valid.