> For the complete documentation index, see [llms.txt](https://agenticai.kasinathanramesh.vip/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://agenticai.kasinathanramesh.vip/section-2-basics-of-langchain-and-langgraph.md).

# Section 2 : Basics of LangChain and LangGraph

## What is LangChain?

* LangChain is a framwework.
* Its a Template.no need to develop from scratch. we ca use the framework and make customization
* Its open Source.
* LangChain is used to develop applications that operate on **Large Language Models (LLMs)**, enabling them to perform tasks such as reasoning, data retrieval, and interaction with external systems.
*

LangChain we can compare with building Materials

{% columns %}
{% column %}
**Building Materials**

1.Cement

2.Water

3.Aggregate

4.Bricks

{% endcolumn %}

{% column %}
**LangCain Tools**

1.LLM

2.Prompt Template

3.Chain

4.Memory

5.AI Agent

6.RAG
{% endcolumn %}
{% endcolumns %}

LangChain recap: Chains, Tools, Memory
\
LangGraph architecture and why it matters
\
Installation, environment setup, and first LangGraph DAG


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