LangChain Flashcards

This page gives you a quick, practical overview of LangChain—the popular
LLM framework for building apps that chain models, tools, and memory.
You’ll see where it fits in an AI stack and how to start using it right away.

In short, LangChain helps developers connect prompts, functions, and external systems into reliable workflows.
Moreover, it supports agents that choose tools dynamically, document loaders for ingestion, and retrieval
for context-aware responses. Because of that design, teams can move from prototype to production faster.

LangChain framework architecture: prompts, tools, memory, retrieval pipeline
Typical workflow: prompt templates, chains, tools, memory, and retrieval combined into one pipeline.

If you plan to ship a full RAG workflow, connect your chains to a vector store.
For example, see our guide on
Vector Stores for RAG with LangChain.
In addition, the official docs explain deployment and best practices in detail.

Deploy LangChain apps with LangServe and FastAPI as REST endpoints
LangServe packages chains behind FastAPI to create secure REST endpoints quickly.

Scroll to the flashcards for a compact refresher. Then, use the links at the end to explore examples and templates.

🧠 LangChain Flashcards
🔗 What is LangChain?
A framework for building LLM-powered apps by chaining models with tools, APIs, and memory.
🧱 What is a Chain?
A sequence of calls—LLMs, functions, or tools—assembled to complete a task.
📦 What is an Agent?
A component that uses model reasoning to choose actions and tools dynamically.
💾 What is Memory?
State that persists between calls, enabling context-aware conversations.
📚 What are Prompts?
Reusable input templates for LLMs; they can be dynamic and parameterised.
🔍 What is Retrieval?
Fetching relevant chunks from vector stores (e.g., FAISS, Pinecone, Chroma) to ground outputs.
🧠 What is an LLMChain?
A basic unit that combines a prompt template with an LLM to return a result.
⚒️ Which tools can agents use?
Web search, calculator, SQL, Python, custom APIs, or even other chains.
📂 What are Document Loaders?
Connectors that ingest PDFs, CSVs, and other files for analysis and retrieval.
⚙️ What is LangServe?
A FastAPI wrapper that deploys chains as REST endpoints quickly and safely.

To get started, build a small chain, add memory once you need context, and then integrate retrieval for accuracy.
Next, containerise your service and expose it with LangServe. Finally, monitor latency and token usage before scaling.

Explore our hands-on guide:
Vector Stores for RAG with LangChain.
For official tutorials and API references, visit the
LangChain documentation.