<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 role of firewalls in computer security. Context: Firewalls play a crucial role in computer security by acting as a barrier between trusted internal networks and untrusted external networks. Answer: [/INST]Firewalls act as a barrier between a trusted internal network and untrusted external networks, filtering incoming and outgoing traffic based on predetermined security rules.</s>