when you detach a DB, you're not deleting or losing any data, simply removing it from the management console. In most cases, once detached, you won't be able to connect via SQL Server provider.
To detach a DB, you can simply right click on the database on SQL Server, and detach. The MDB and LDB files will still exsist in the current directory.
To "attach" is when you bring over an existing MDB and LDB files, or the Database. It's new data to your server, or console, to manage.
To attach, you select attach and select the MDB file from the directory they are found.
Do you follow so far? Is that what you needed or do you need more, I can still try to help.