Langchain is a Python framework to build applications on top of large-language models (OpenAI, Llama, Gemini).Building on top of LLMs comes with many challenges:
Gathering and preparing the data (context) and providing memory to models
Orchestrating tasks to match LLM API requirements (ex, rate limiting, chunking)
Parse the different LLM result format
Langchain comes with a set of high-level concepts and tools to cope with those challenges: