A client is a legally and organizationally independent unit within the R/3 system. All the settings which are common in entire organization will be specified at client level. for example, a company group, a business unit, or a corporation.
After the completion of r/3 software installation in the first phase of any r/3 technical part of implementation in an organization, client copy will be done. This client copy will be done from the one of the standard clients included in the package. Customers can make tests, can use them for training, or can start real customization in the copied client. We should not disturb standard client at stage of implementation. We can copy clients from standard clients any number of times.
SAP System’s technical structure will be defined by clients and each client contains it’s own master records and set of tables. There are two types of customizing, they are client specific and cross client customizing. This depends on which business data is configured. Cross client customizing is valid for all the clients in the SAP R/3 System.
SAP comes with three standard clients. They are 000, 001, and 066.
Client 000 contains a simple organizational structure of a test company and includes parameters for all applications, standard settings, configurations for the control of standard transactions and examples to be used in many different profiles of the business applications. For these reasons, 000 is a special client for the R/3 system since it contains the client−independent settings.
Client 001 is a copy of the 000 client, including the test company; if this client is configured or customized, its settings are client−dependent. It does not behave like 000. It is reserved for the activities of preparing a system for the production environment. SAP customers usually use this client as a source for copying other new clients.
Client 066 is reserved for SAP access to its customers’ systems to perform the Early Watch service. The R/3 system includes tools for creating, copying, transferring, resetting, deleting, and comparing clients. When the loads of individual clients differ, the buffer manager of the application service is able to respond and allocate resources appropriately.