Prompt injection is a significant and evolving AI security threat, where attackers manipulate large language models (LLMs) by embedding deceptive instructions to override system prompts, extract sensitive data, and subvert AI-driven decision-making. Unlike traditional cybersecurity attacks that target code vulnerabilities, prompt injection exploits the model's instruction-following logic, using language to influence the system's behavior. This threat is identified as the top AI security risk by OWASP and poses challenges for enterprises deploying AI applications, particularly in sensitive domains like finance and healthcare. Despite advancements in LLMs, attackers continue to refine their methods, necessitating a proactive and multi-layered security approach that includes real-time detection, continuous adversarial testing, and adaptive defenses to safeguard AI systems.