A blue-green deployment is a software deployment technique where two identical environments (X and Y) are used to switch between the old and new versions of the software. In this scenario, the X environment is patched/upgraded and tested while the Y environment is still serving the consumer workloads. Upon successful testing of the X environment, all workload is sent to this environment, and the Y environment is then upgraded before both environments start to manage the workloads. This is an example of a blue-green deployment, where one environment (blue) is active and serving the production traffic, while the other environment (green) is idle and ready to be updated. The advantage of this technique is that it allows for fast and easy rollbacks in case of any issues with the new version, as well as zero downtime for the users.