The $Locale value provider is a global value provider that returns information about the current user's locale, such as the date format, time format, number format, currency format, and currency symbol. You can use the $Locale value provider to format the data in your Aura components according to the user's locale preferences. The $User global variable returns information about the current user, such as the name, email, profile, and role, but not the locale preferences. The $Label global value provider returns custom labels that are defined in your Salesforce organization. Custom labels are used to create multilingual applications that can be translated into different languages. A hierarchical custom setting is a type of custom setting that lets you set different values for different profiles or users. You can use a hierarchical custom setting to store user preferences, but you would need to write code to retrieve and apply them to your Aura components. Reference: [$Locale Value Provider], [$User Global Variable], [$Label Global Value Provider], [Custom Settings]