The Adapter Framework 
The Adapter Framework
Purpose
Adapters are interfaces between different systems. Data exchange in the new SAP CRM environment is based on the Adapter Framework.
Implementation Considerations
Refer to collective note 156102 which contains all the current notes on the Adapter Framework.
Features
The Adapter Framework consists of the following main components which are used as synchronization mechanisms between the CRM Server and the participating sites:
The initial load handles the entire data transfer of defined objects from the R/3 back-end system.
For example, it provides change information from the R/3 back-end system for the CRM Server. Delta data transfer means that once the initial data transfer has been completed, permanent data is available.
R/3 back-end users can make changes to existing customer master data or create new requests. This delta information must be forwarded to the CRM Server.
Here the R/3 back-end system is supplied with information from the CRM Server.
The different datasets are synchronized. This can be controlled in time slots or can be triggered manually. You can restrict the synchronization, for example, to one request only. The synchronization component can be used everywhere where a delta data transfer cannot be used. It can also be used to clean up inconsistent data.