Active is the normal state of the form element. It is available for user interaction.
Focus is initiated when the user interacts with the field. We currently allow the browser to provide default styling for focus states (except for the text input and textarea as browsers are inconsistent in their use of a focus state here).
Read only indicates that a field is active, but not editable.
Disabled state is a form input that is unavailable for interaction.
Error is used when a field has been filled out incorrectly. This state should always be paired with an explanatory message.
Focused Error appears when the user focuses an input with an error.