<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 a computer network? Context: The purpose of a firewall in a computer network is to protect against unauthorized access and cyber attacks by monitoring and controlling incoming and outgoing network traffic. Answer: [/INST]A firewall is used to protect against unauthorized access and cyber attacks by monitoring and controlling incoming and outgoing network traffic.</s>