LangChain has implementations for older language models that take a string as input and return a string as output. These models are typically named without the "Chat" prefix (e.g.,Ollama,Anthropic,OpenAI, etc.), and may include the "LLM" suffix (e.g.,OllamaLLM,AnthropicLLM,OpenAILLM, etc.). These models implement theBaseLLM interface.

Users should be using almost exclusively the newerChat Models as mostmodel providers have adopted a chat like interface for interacting with language models.