Blue-Green Deployment is a software release management strategy that reduces downtime and risk by running two identical production environments, referred to as "blue" and "green." At any time, one environment is live and serving users, while the other is idle and can be used for testing new features or updates. When a new version of the application is ready, it is deployed to the idle environment. Once verified, traffic is switched from the live environment to the updated one. This approach allows for quick rollbacks if issues arise, ensuring a smoother transition and improved user experience.