DTAP infrastructure
RWS recommends running multiple instances of Tridion Sites in parallel to manage the development process and clearly separate the project implementation phases and use Content Porter to port data from one Tridion Sites environment to another. Development, Test, Acceptance and Production (DTAP) is the recommended infrastructure for a Tridion Sites implementation.
DTAP enables different users to manage different types of content on different Content Manager servers: the creation and management of content is distributed over several machines to prevent different types of content from getting in each other's way. You then use Content Porter to port data from one Tridion Sites environment to another.
The following diagram shows a typical hardware setup for a DTAP environment: a single-machine setup for Development and Test, and a multiple-machine setup for Acceptance and Production. Everything except the Acceptance Live Server and Production Live Server lives inside the local network.