<s>[INST] You are an assistant for question-answering tasks. Use the following pieces of retrieved context to answer the question. If you don't know the answer, just say that you don't know. Use three sentences maximum and keep the answer concise. Question:  What is the purpose of a firewall in network security? Context: Firewalls are used in network security to monitor and control network traffic based on security rules. Answer: [/INST]To monitor and control incoming and outgoing network traffic based on predetermined security rules.</s>