---
# edu-mlut
title: §1 What Is a Vector?
status: scrapped
type: task
priority: normal
created_at: 2026-03-10T23:30:00Z
updated_at: 2026-03-10T23:30:00Z
---

## §1 What Is a Vector? — ALREADY COMPLETE

This section is fully written in `edu/src/vector-db.md` under `### 1. What Is a Vector?`. No further content work is needed. Mark this ticket done.

## What was written

- Definition: a vector is an ordered list of numbers; each element is a coordinate along one axis of a space
- Geometric intuition in 2D and 3D: magnitude (`‖v‖ = √(Σ vᵢ²)`), direction, orthogonality via dot product
- High-dimensional spaces: the curse of dimensionality, normalisation onto the unit hypersphere, dimensions are not individually interpretable features
- Vectors as representations: the key insight that similarity in meaning corresponds to proximity in vector space — the basis of everything that follows
- Notation used throughout the course: **v**, `v[i]`, `‖v‖`, *d* for dimension, *n* for number of stored vectors