<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 access control in computer security. Context: Access control restricts unauthorized users from accessing sensitive data or systems. Answer: [/INST]It restricts unauthorized users from accessing sensitive data or systems.</s>