Introduction
Almost everything a machine-learning model touches is a vector: a photo, a sentence, a customer, the weights of a neural network, the direction a model should move while learning. Before any formula, it helps to know that the word "vector" is used in three different but connected ways:
- a physicist sees an arrow with a length and a direction,
- a programmer sees an ordered list of numbers,
- a mathematician sees any object you can add and scale.
All three views are correct, and switching between them is a skill you will use constantly. This topic builds each view and then connects them to data.