An environment is defined as a full website or application stack containing everything the website or application needs to deliver features and content to users. This includes, but is not limited to, the following:
A dedicated parcel of server space
Memory
A database
An operating system
Application services
Most developers who work with several environments use at least two different environments:
A development environment, where new code can be created and tested.
A production environment, where the live website and its data exist.
Web development projects should use at least two or more environments. For example, a third environment for staging can be useful for merging production data with newly developed code for extensive testing purposes.
Notes for Cloud Platform users
Acquia’s hosting services use several environments, which are more explicitly defined under the Multiple environments: local, dev, stage and prod section in Key concepts in Cloud Platform.
When in use on Cloud Platform, environment names are abbreviated and added to your website’s name to create the docroot directory name. One example of this in use is the syntax to sign in to your server using SSH.