High-level description of SQL and its security

re:> your security section still not right
I may have many things wrong. What will be helpful is take a sentence or two and write it they way it is right. By just saying it is not right, is not helpful at all.

re:> The analogy with a restaurant still not good.
I intend to keep this analogy but modify it in such a manner that makes sense. You are welcome to help me on that if you can come up with a better way of saying it. Or, make a better analogy.

re:> The authentication methods are two only
Yes, my bad. They are:
1. Windows level.     <-- authentication
2. Sever Level.          <-- authentication
3. Database Level.   <-- what you will name this? permission?  privilege?

What is the a common word (or category) for all three?

re:> definition of a Database Management System?
What about it. What is that you want me focus about this? Do you have a particular point you want me to focus on it?

re:> followed by the definitions of Instance, Database, Login, User and Schema.
The same as above.

re:> when you have these concepts in your mind
I think I have them in my mind hence this write-up. I probably miss some crucial aspects of them but you never give a clue in your post. I just wonder what exactly you mean. It will be helpful to give me something to go by.

I know that is not probably your style, but you are not telling me what is the problem just hinting there is problem.

Regards,

Mike

Who are the users for this writing are:
- Myself to make sure I understand it.  <<< mainly this
- My college kid and friends.
- Number of my ex-project managers (now friends) who could really use some knowledge about SQL Server.
- All above who also need to use some basic T-SQL.