A Greenfield approach is a brand-new implementation , where companies then add their needed configurations and customizations. This approach provides a clean slate to start from, does not carry over needless customizations and technical debt, and provides a solid foundation for business process re- engineering.
A greenfield deployment is the design, installation and configuration of computer infrastructure where none existed before, for example, in a new office. In contrast, a brownfield deployment is an upgrade or addition to existing infrastructure using legacy components.