See input (type="submit").

This is single character key that either gives focus to a submit element or activates a form control or link action.

Specifies whether the element is available for user interaction. When set to true , the element cannot receive focus or be modified by the user

Gives focus from the current submit object, at which time the submit object's onfocus event fires.

This is a number that indicates the sequence of this submit element within the tabbing order of all focusable elements in the document.