this is llm: question=st.text_input("your question") llm=OpenAI(temperature=0.9) if prompt: response=llm(prompt) st.write(response) then if we need to execute a prompt we have to crate llm chain: from langchain.prompts import PromptTemplate from langchain.chains import LLMChain question=st.text_input("your question") llm=OpenAI(temperature=0.9) template="Write me something about {topic}" topic_template=PromptTemplate(input_variables=['topic'],template=template) topic_chain=LLMChain(llm=llm,prompt=topic_template) if prompt: response=topic_chain.run(question) st.write(response) I am confused because we used llm(prompt) in the first example, but we created LLMChain(llm=llm,prompt=topic_template) in the second example. Could you please explain the difference between these two approaches and when it's appropriate to use one over the other? Continue reading...