Large language model (LLM) guardrails are frameworks and mechanisms designed to ensure the reliable and secure performance of AI applications, particularly in high-stakes enterprise environments. Given the non-deterministic nature of LLMs, these guardrails are crucial for aligning model outputs with ethical, operational, and regulatory standards, thereby preventing risks such as data leakage, biased or harmful responses, and inaccuracies. They encompass various types, including security, information, ethical, compliance, contextual, and adaptive guardrails, each tailored to address specific challenges like data privacy, misinformation, and evolving user needs. Best practices for implementing these guardrails include establishing customized model constraints, conducting red teaming and vulnerability assessments, continuous monitoring, real-time auditing, and integrating feedback loops for ongoing improvement. Such measures are essential for maintaining user trust and ensuring AI systems operate in a manner consistent with business objectives and legal requirements.