# RAG Clearly Explained

DevFeed: [RAG Clearly Explained](<https://devfeed.tech/articles/rag-clearly-explained-18035.md>)

Original publisher: [Read original article](<https://blog.levelupcoding.com/p/rag-clearly-explained>)

Author: Nikki Siapno

Published: 2026-07-15T14:15:13Z

Content type: tutorial

Language: en

Sources: [Level Up Coding System Design Newsletter](<https://devfeed.tech/sources/level-up-coding-system-design-newsletter.md>)

Topics: [Retrieval Augmented Generation (RAG)](<https://devfeed.tech/topics/retrieval-augmented-generation-rag.md>), [Large Language Model](<https://devfeed.tech/topics/llm.md>), [AI search](<https://devfeed.tech/topics/ai-search.md>)

Tags: [model](<https://devfeed.tech/tags/model.md>), [rag](<https://devfeed.tech/tags/rag.md>), [retrieval](<https://devfeed.tech/tags/retrieval.md>), [retrieval-augmented-generation-rag](<https://devfeed.tech/tags/retrieval-augmented-generation-rag.md>), [vector-search](<https://devfeed.tech/tags/vector-search.md>)

## AI overview

A tutorial explaining Retrieval-Augmented Generation (RAG), a system pattern that retrieves relevant external information at query time and provides it to an LLM as context. It distinguishes RAG from fine-tuning, plain search, and vector search, and outlines knowledge preparation using chunks and searchable indexes.

## Source excerpt

The mental model every engineer should have.