Each standard HTML form control and ARIA widget role must have a label that is unique on the page. Labels that are unique make it possible for people to understand the different purposes of form controls on the same page.

What makes a good ARIA-label?

implicit landmark elements: such as header , footer , nav , main , aside , section , and form . explicit landmark elements: such as an element with role="navigation" . widget role elements: such as an element with role="dialog" or role="tooltip" (there are 27 widget roles in ARIA 1.1).

When should ARIA labels not be used?

It means don't use ARIA when semantic markup already conveys the same information. For example, the [role] property is part of ARIA. One available role is heading . Its purpose is to let screen readers and other AT know that an elements that's not an h* element is supposed to be a heading.