How you split your documents decides what retrieval can find, and it is the most underrated lever in RAG. Chunk too big and you retrieve a wall of text with the answer buried and diluted; chunk too small and you sever the context that made the answer meaningful.

This lesson teaches the tradeoff and the practical strategies (by size, by structure, with overlap) so you split documents in a way that preserves meaning. Most bad RAG is bad chunking, and fixing it is often the single biggest quality jump you can make.