Account group tags help to filter various lists to streamline the user experience to focus on the accounts most relevant to them.
Required User Roles: Only Global Admins or Account Admins have permissions to add/modify Account Group Tags.
Global Admins can modify all users and Account Admins can modify users other than Global Admins.
Account group tags are a way to automatically filter lists to be only the items most relevant for that user. The account group tag needs to be assigned to the account as well as the user so that all filterable lists will pre-filter the view for only accounts that have that tag assigned.
Account group tags are user specific and will create a view that is different from other users who are not assigned that tag. A user can still view other accounts if needed, but they will be out of the way for the most used lists.