In SQL Server 2005, the security model is divided into three areas namely authentication, authorization, and encryption.
Authentication is the process of identifying the logon information of a user who is connecting to and accessing databases on the SQL server.
Authorization is the access rights to database objects that are given to a user after the logon process is successfully completed (authenticated).
Encryption, which is entirely new in SQL Server 2005, is the transmitting of valuable information in formats that an unauthorized user cannot easily access. Although there were undocumented stored procedures available for encryption in SQL Server 2000, they were hardly popular among the database community.
How to Create schema?
1. create schema [aa] authorization [db_accessadmin]
The following script will create a user called tt with password s# and with SELECT permission on schema Accounts.
CREATE LOGIN tt WITH PASSWORD='s#'
GO
USE AdventureWorks
GO
CREATE USER tt FROM LOGIN tt
GRANT SELECT ON SCHEMA::[Accounts] TO [tt]