Standard Users in SAP.

Users

SAP*

SAP* is the super user of SAP system and used for doing client copy. SAP* is the only user in the SAP System that does not require a user master record, but that is instead defined in the system code itself. SAP* has by default the password 'pass', as well as unlimited system access authorizations. When you install your SAP System, a user master record is defined for SAP* with the initial password as the master password (set during installation) in clients 000 and 001. The presence of a SAP* user master record deactivates the special properties of SAP* and standard password 'pass'. It has only the password and the authorizations that are specified for it in the user master record.
When temporary license expires only SAP* user is allowed to login to client 000 to install permanent
license.

DDIC
 
It is the maintenance user for ABAP Dictionary and software logistics. It is used for any upgrade or installation type of work like,
1. TMS Configuration,
2. Applying Support Packages,
3. Applying Add-ons,
4. Implementing SAP Notes etc.

• Best practice is not to use DDIC user but create a new user by copying from DDIC.
• DDIC is the only user that is allowed to log on to the SAP System during an upgrade.
• DDIC is hard coded to do some things other IDs cannot and restricted from doing some things that other IDs can.

EARLYWATCH
 
The SAP EarlyWatch service uses this user. This user should only be used for EarlyWatch functions like monitoring and performance analysis.
Default users in each clients,

Client 000
Username: SAP* --> short for SAP Star
Password:
Username: DDIC --> copy of SAP*, short for Data Dictionary
Password:

Client 001
Since Client 001 is a copy of Client 000, it has the same users and passwords as in Client 000.

Client 066
Username: EARLYWATCH
Password: support

New Client
Username: SAP*
Password: pass