Azure Key Vault is a cloud-based service that securely stores and manages sensitive information such as secrets, passwords, API keys, encryption keys, and digital certificates. Instead of hardcoding credentials in application code or configuration files, developers can securely retrieve them from Azure Key Vault at runtime. In enterprise applications, Azure Key Vault improves security by centralizing secret management, enforcing access policies through Microsoft Entra ID (formerly Azure Active Directory), and maintaining audit logs of all access attempts. It also supports automatic key rotation and certificate renewal, reducing administrative effort and minimizing security risks. By integrating Azure Key Vault with services like Azure App Service, Azure Functions, Virtual Machines, and Kubernetes, organizations can build secure applications while following security best practices and compliance requirements.