An environment is a workspace shared by several people.
Several projects can be created in a given environment.
An environment is a closed workspace where a team member can contribute to one or several projects. Can reach projects of the environment only people who were invited by the administrator of the environment or the project manager. It is considered as a private space.
An environment can be managed by one or several administrators.
You can create as many environments as you want. If you have critical customers it allows to create them a dedicated environment. Customers can then see only projects of the environment in which they were invited.
Other companies use two environments, one for the internal projects and an other one for the projects with subcontractors.
Others use only a single environment and it fulfils most of their needs.
In environment you can create dependencies between projects.