Client landscape: Basic layout : dev -testing- production also – Sandbox server . for trial and error – Development server for actually creating transports (CTS) – Global server. If you have global implementations at different client locations (eg; Canada, US, UK) (for testing purposes with actual master data as well) – Testing server.(for regression testing purposes before moving to production, integration etc..) – Production server is the actual production system The clients could be variable and could be created to a specific server . usually a developed. where abap, functional would mess around. say : client 100-functinal consultants ,client 300- abapers ,client 400- other users(like super etc)