<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:  Describe the purpose of firewalls in Computer Security. Context: The purpose of firewalls in Computer Security is to serve as a barrier between a trusted internal network and untrusted external networks. Answer: [/INST]Firewalls serve as a barrier between a trusted internal network and untrusted external networks.</s>