Blue-green deployment is a software development technique which uses two production environments (blue & green) to make software deployment easier and safer.| Optimizely
A feature toggle is a mechanism that allows code to be turned “on” or “off” remotely without the need for a deploy.| Optimizely
Feature management refers to the process of developing, delivering, and optimizing new features. Teams test and release features to specific users or groups.| Optimizely
Feature flags are a software development technique that turns certain functionality on and off during runtime, without deploying new code.| Optimizely