Explanation
Blue-green deployment is a technique that reduces downtime and risk by running two identical production environments called Blue and Green. At any time, only one of the environments is live, with the live environment serving all production traffic. For this example, Blue is currently live and Green is idle.
https://docs.cloudfoundry.org/devguide/deploy-apps/blue-green.html
Canary deployments are a pattern for rolling out releases to a subset of users or servers. The idea is to first deploy the change to a small subset of servers, test it, and then roll the change out to the rest of the servers. ...
Canaries were once regularly used in coal mining as an early warning system.
https://octopus.com/docs/deployment-patterns/canary-deployments