What is th difference between Sap lock and database lock?

A “SAP lock” is named “enqueue lock”, the enqueue is on a much higher level, e. g. a complete sales document is locked there whereas in the datbase usually only row locks exist. Since SAP runs on more database than Oracle (thanx god) one needed to have a mechanism, that is database independent and on a higher level.

What is osp$ mean?

OPS$ is the mechanism the adm users uses to connect to the database.