SAP systems are organized into instances, each of which contains one or more clients. Examples of instances are DEV (for development and configuration), QA(for quality assurance) and PRD (for the productive system). There may be more instances, but that would be the minimum setup of any SAP system Landscape.
Each instance may consist of more than one client. The clients are typically identified by a three-digit number, such as 100, 110, 120, 200, etc. Each client within an instance can share SAP R/3 programs, but will have its own transactional data. Some configuration will affect all of the clients in an instance, but some configuration will only affect the client in which it has been performed.
In order to transport configuration changes to another SAP instance, the changes must be included in a “change request.” One or more configuration changes can be included in the same change request, or each configuration change can have its own change request. Consult with the project team and/or the basis team to determine the best approach for transporting change requests. If each configuration change generates its own change request, many change requests can be time consuming for the basis team to transport.