It is reasonable to frame generative AI (Gen AI) as having four core components—embedding, vector search, retrieval-augmented generation (RAG), and large language models (LLMs)—especially in the context of building practical systems that leverage Gen AI. Here's how these components fit into the picture:
# 1. Embeddings
- Definition: Embeddings are dense vector representations of text, images, or other data that encode their semantic meaning.
- Purpose: Convert data into a numerical form that models (e.g., LLMs) can understand and compare.
- Role in Gen AI:
- Used for semantic similarity comparisons (e.g., finding related documents).
- Essential in powering vector search systems.
Example Tools:
- OpenAI’s
text-embedding-ada-002 - Sentence Transformers
- Hugging Face models for embeddings
# 2. Vector Search
- Definition: A technique to efficiently search and retrieve data from a collection of vectors based on their similarity in high-dimensional space.
- Purpose: Enable fast and accurate retrieval of relevant data from large datasets using similarity metrics like cosine similarity.
- Role in Gen AI:
- Supports retrieval-based tasks by locating relevant information from large knowledge bases.
- Integrates with embeddings to provide context for LLMs.
Example Tools:
- Pinecone, Weaviate, Vespa, Milvus
- Elasticsearch with dense vector support
- FAISS (Facebook AI Similarity Search)
# 3. Retrieval-Augmented Generation (RAG)
- Definition: A framework that combines information retrieval with generative models to produce contextually informed outputs.
- Purpose: Enhance generative AI by grounding responses in retrieved, relevant documents or knowledge.
- Role in Gen AI:
- Resolves the knowledge cutoff issue in LLMs by augmenting them with real-time, domain-specific knowledge.
- Reduces hallucination by anchoring answers in factual references.
Typical Workflow:
- User query → Embed the query.
- Search embeddings in a vector database (vector search).
- Retrieve relevant documents.
- Feed the retrieved context to the LLM to generate a grounded response.
Example Applications:
- Customer support systems
- Document Q&A
- Knowledge management tools
# 4. Large Language Models (LLMs)
- Definition: Foundation models trained on massive corpora to generate and understand human-like text.
- Purpose: Generate coherent, context-aware, and creative responses.
- Role in Gen AI:
- Serve as the generative backbone.
- Can work standalone or in tandem with embeddings and vector search for RAG workflows.
Popular Models:
- GPT (OpenAI)
- PaLM (Google)
- LLaMA (Meta)
- Falcon, Cohere, etc.
# Relationship Between the Components
These components often work together as part of a pipeline:
- Embeddings: Represent queries and data semantically.
- Vector Search: Retrieve the most relevant documents using embeddings.
- RAG Framework: Incorporate retrieved information into LLM inputs for context.
- LLMs: Generate human-like responses enriched by retrieved knowledge.
# Why This Categorization Makes Sense
- Embeddings and vector search provide the semantic understanding and retrieval capabilities.
- RAG acts as the contextual glue that integrates search and generation.
- LLMs provide the core generative functionality.