Vector
Also: feature vector, column vector
An element of ℝⁿ: n numbers that can be added component by component and scaled. In ML a vector usually holds one example's features, one embedding, or one layer's activations.
Example
A house with 3 bedrooms, 120 m² of floor space and an age of 15 years becomes the feature vector (3, 120, 15), a point in 3-dimensional space.