What about the permissions and types of user account in Windows Vista?

Please refer to the following contents
  

In Windows Vista, the new function (User Account Control (UAC)) is added to strengthen security.
After setting UAC to valid, every operation requires the user’s permission.
Please refer to the following related items for further details.
[Windows Vista] About user account control

There are three different kinds of user accounts as below:
Each account type gives the user a different level of control over the computer.
•Administrator account
Administrator account can access all files on the computer and can carry out any change needed.
In older versions of the Windows operating system, in order to change the configuration of the computer, it would be necessary to log on with an administrator account.
But in Windows Vista, if you use a Standard account or Guest account to log on, you do not need to log on with the administrator account because of UAC. 
•Standard account
Compared with computer administrator, the account is forbidden from some management functions.
•Guest account
Provides an account to user’s who does not have a user account.
Please refer to the following related information for further details.
[Windows Vista] About Guest Account