When setting up DY 365 Sales Ent. does it create a new environment, or should I add it to my existing company environment? Does it create a new one for each Module?

When setting up DY 365 Sales Ent. does it create a new environment, or should I add it to my existing company environment? Does it create a new one for each Module?
Hi DCXTaaS,
You can create a new environment or use an existing environment(This environment must be Dynamics 365 apps–enabled.),both of which are possible.
Set up Dynamics 365 Sales (Dynamics 365 Sales) | Microsoft Docs
An environment is a space to store, manage, and share your organization's business data, apps, chatbots, and flows. It also serves as a container to separate apps that might have different roles, security requirements, or target audiences. How you choose to use environments depends on your organization and the apps you're trying to build.