When to Use a Button
Buttons give users a path to an action, referred to as a call to action or CTA. They should only be used to drive users to apply, complete a form, make an appointment, or any other major action you want users to perform.
Do not use a CTA in place of download links or navigation. In such cases, a hyperlink or proper navigational element should be used. Too many buttons overwhelm users so ask yourself, “am I asking the user to do something?” If your answer is no, you don't need a button.
Different styles are applied to the button depending on the importance and kind of action the CTA is initiating. CTAs should never have texts that is two lines long.