In the SAP landscape, a client is an entity with independent data and information.So let’s check the default SAP clients a little bit closer…

000,001 and 066 are default clients of SAP that you get at the time of installation and you cannot use it for production.

000 this client is called as golden client which is provided by SAP as template/refrence client , you cannot use this client in production processing either.

001 this client is called as configuration client which have all the SAP standard customizing client.

066 is the Earlywatch client for monitoring and performance to SAP use.

Also there is other standart SAP client is IDES ;

800 is the IDES client and contains ides test data to use it for the customers.

And all these clients are comes with standart users : SAP* and DDIC

SAP* Default Password : 06071992

DDIC Default Password : 19920706

If your parameter “login/no_automatic_user_sapstar” value equal to 0 (zero) then you can regenerate the SAP* user with default password “PASS” after deletion process.

Also you can use EARLYWATCH user with password SUPPORT on client 066