HashiCorp Vault provides a secure way to manage and rotate database credentials in Kubernetes applications. The integration allows operators to provide dynamically generated credentials for applications, managing the lifecycle of credentials, rotating and revoking as required. The process involves creating roles, connections, and policies to control access to secrets, using metadata annotations to inject dynamically generated database secrets into a Kubernetes pod. The integration automatically handles authentication with Vault and manages the secrets, allowing the application to read the secrets from the filesystem.