Reference · Glossary
Vector
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A **vector** is an ordered list of numbers. In AI, embeddings are vectors that place meaning in a space where similar items are close together.
#When to use
Similarity search, clustering, recommendations, and RAG retrieval — anywhere “nearness” should track meaning, not exact strings.
#When not to
Exact ID lookups, keyword legal matches, or tiny feature sets where a simple key-value store is enough.
#Practical tips
- Same embedding model at index and query time
- Normalize or use cosine similarity consistently
- Dimensionality and model choice affect recall and cost
#Example
"refund policy" → [0.12, -0.44, ...]
"money-back guarantee" → nearby vector
"shipping rates" → farther away#Learn next
- Lesson: `vectors-and-similarity`
- Related: embedding, vector database