A client is a self-contained unit in commercial, organizational, and technical terms, with its own user master data and set of table key ranges.
Data in an SAP system can be divided into two categories: client-specific data and cross-client data.
1. Client-specific data, such as user master and application data, which affects only one client.
2. Cross-client data, such as cross-client customizing data and all Repository objects, which affects the whole system environment.
All users login to one specific client in a SAP system and every client has its own application data.
Client specific data = User masters data+ customizing data+ Application data
User masters data – parameters, authorizations, user groups.
Customizing data – documents type, assignments, and organizational data.
Application data – business transaction data and material master data.
Three clients are there in every system.
000 -> this client is a golden client and is used to do TMS configuration, support pack upgrade, language installation and while running SGEN. It should not be used otherwise since it contains master data and transactional data.
001 -> this client is similar to 000 and the only difference is that in solution manager system it is an active client.
066 -> it is also known early watch client as it is used to perform early watch functions like monitoring and performance tuning.
Data from different clients is kept at a different place at kernel level. A table may contain data from different clients but everything is bifurcated through the use of where-clause.
Using client concept a company can integrate its several subsidiaries, suppliers and vendors in a single system.
For example: A company XYZ wants data of its 2 suppliers and 1 subsidiary to be in the same system. For this we can define one system having 3 clients.
2 clients having data of each supplier and 1 client for its subsidiary.
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