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+## Chapter 1: What is LangChain?
+LangChain is an open source library for simplifying AI application development. It provides a set of tools to efficiently perform various AI-related tasks, with a focus on Large Scale Language Models (LLMs).
 
+```
+from langchain import LLMChain
+from langchain.llms import OpenAI
+from langchain.prompts import PromptTemplate
+
+# LangChain
+llm = OpenAI(temperature=0.9)
+prompt = PromptTemplate(
+    input_variables=["product"],
+    template="What is a good name for a company that makes {product}?",
+)
+chain = LLMChain(llm=llm, prompt=prompt)
+
+
+print(chain.run("eco-friendly water bottles"))
+```