this is a question of the course : Database System.
Please help me, i have no idea about it. Thank you.

I'd probably start with Microsoft's definition, then build on that if necessary.

-PatP

in the case of OS terminology service is said to "Background processes" which are named by "Daemon processes" in Unix.
But I could not underestand the relationship between this and database system.
in Oracle terms it referred to database name.
-Good luck