Whit members management you can manage your users and even contact them if neccesary. There are two kinds of users in your system.

  1. Admin Users
  2. Normal Users

Normal users are the ones who subscribe to your site when using Members module and will be able to comment, rate and modify their own account page. Comments can also be made available to guest users too but usualli that's not a good idea.

In the admin an administrator will be able to manage these users, Suspend them or even delete them if they for some reason broke the rules. When needed you as an admin will be able to contact them at once using the Mass Email option.

NOTE: when using the mass email option please make sure to make the users awear at the sign up process that they agree to receive newsletter emails from your site and give them on option to opt out of this feature as otherwise you may end up spamming people and that's not legal in any country as I know!

You will be also able to give permissions to users if you are a super admin (meaning having full access to anything). These permissions are done by specifying the adminpath that you would like for a user to have access to and selecting a permission to it (Read or Write). 

IMPORTANT: an admin user who has no permissions set at all will have full access to the admin! .. and if a user has full access to the admin/members/users he will be able to change his own permissions so it's like having full access.

Because there are two kind of users a user is not able to access the admin area unless his Admin status is checked too, so without this checked even if the user has admin permissions set he won't be able to access the admin.

With members management you should be able to keep track of your users and keep order in your site while future modules may extend user data to give you more flexibility.