Phase 2 · Math, when you need it · Linear algebra
Vectors
A list of numbers as a point or an arrow in space.
Why it matters
A computer can't look at a customer, a word or a photo. It can only do sums. So before any AI model can work with something, that thing has to become a list of numbers. That list is called a vector. A customer becomes [orders, average spend, days since last visit]. A word becomes a list of a few thousand numbers that capture its meaning. Once you can picture these lists as arrows, the big ideas later in the course (similarity search, neural networks, attention) stop being mysterious. They are all things you do to arrows.
What you'll be able to do
- See a vector three ways: a list of numbers, a point, and an arrow
- Read vector notation: bold letters, components, dimension
- Turn records like customers or campaigns into feature vectors with a fixed order
- Explain why every input to a model ends up as a vector
Before this lesson
Next in this phase: Vector arithmetic and length