A client is simply the first field of every data record in tables that are not overall system-related. It is a way to have different groupings of data within one database. Originally multiple companies ran SAP from one system and database in a time sharing fashion. The ‘client’ was the company they were doing business with. They added more companies and they became more clients in the system. The design created to separate one company’s information from another a dded a ‘client’ or mandt field to each client-related data table. Behind the scenes any data access additionally specifies the client number that the user logged into.
Using the MARA table (general material data) as an example, the first data field is mandt followed by material number and other material fields. If you logged into client 300 and in an ABAP program did a database query like <b>select * from mara</b> SAP in the backgreound is actually querying the database as <b>select * from mara where mandt = 300</b>.
Clients can be used for separating data for multiple companies or multiple divisions or just created for testing a process or dataload. Clients can be created, copied and deleted.
client is the work area for particular process. example we can take the 800 client for particular work.810 for debit process.800 for credit process.