LangChain supports both Python and javascript. This book focuses on the javascript version of LangChain. Save your time and learn up to 3X faster with a structured learning system that’s carefully crafted for beginners. LangChainJS For Beginners will help you harness the power of LangChain and javascript to develop AI-powered applications. In this book, I'll be using a step-by-step, practical approach so that you can build cutting-edge AI solutions using LangChain and javascript. By the end of the book, you will understand how to build a Next.js web application that harnesses the power of LLMs such as OpenAI's GPT and Google's Gemini. A Large Language Model (LLM for short) is a Machine Learning model that can understand and generate an output that humans can understand. LLMs are usually trained on a vast amount of text data available on the internet so that they can perform a wide range of language-related tasks such as translation, summarization, question answering, and creative writing. Examples of LLMs include GPT-4 by OpenAI, Gemini by Google, Llama by Meta, and Mistral by Mistral. Some LLMs are closed-source, like GPT and Gemini, while some are open-source such as Llama and Mistral. LangChain is an open-source framework designed to simplify the process of developing a LLM-powered application. LangChain enables you to integrate and call LLM which powers generative AI applications by simply calling the class that represents the model. Under the hood, LangChain will perform the steps required to interact with the language model API and manage the processing of input and output so that you can access different LLMs with minimal code change.