A vector database stores data as lists of numbers called embeddings, which lets it search by meaning instead of matching exact keywords. It's the piece behind a lot of recommendation systems, RAG apps, and AI agents.

We just published a comprehensive course on the freeCodeCamp.org YouTube channel that will teach you how vector databases work, starting with the math and ending with a working semantic search project. This course is from codeEdx, whose instructor has worked as a software engineer for 15 years and as a lead AI engineer for the last four. No prior knowledge is required.

In this course, you will learn:

  • Vectors & Similarity Math
    Learn what a vector is and how cosine similarity and Euclidean distance measure how close two pieces of data are.
  • Tokens & Tokenization
    See why AI models can't read raw text and how a tokenizer splits a word like "indivisible" into more than one token.
  • Embeddings & Embedding Models
    Understand how text becomes vectors that capture meaning, including the classic king minus man plus woman equals queen example.
  • Generating Embeddings with Gemini
    Follow a live demo using Google's Gemini embedding model, then visualize the results in 3D with principal component analysis (PCA).
  • Inside a Vector Database
    Explore the storage, indexing, and query processing layers, and how IVF and HNSW indexes avoid slow brute force search.
  • Semantic Search with ChromaDB
    Create a Chroma client and collection, store your embeddings, and run queries that return results based on meaning.

Watch the full course on the freeCodeCamp.org YouTube channel (1.5-hour watch).