When you a workbook, you control the ability users have to make changes to the file?

When you protect a workbook, you control the ability users have, to make changes to the file.  This is to prevent other users from making changes, functions like adding, moving, deleting, or hiding worksheets, and renaming worksheets, you can protect it with a password. 

Good job, jason. he's more successful than i'll ever be loolll