Let's say you had a user login created in either Oracle or SQL Server and your login had been granted the authority to create database objects (e.g. tables, stored procedures, views). When you create those tables, in this case the Employees table, the table will be prefixed with your login (e.g. Tom.Employees). You are effectlvely the owner of the table and it belongs to you. No one else can access that table unless they are granted permission.
Let me know if this needs further explaination.