[dalore]

Should "book now" be a button or a link?

It is an action, but it navigates you to the booking page. That page should have a url and should be able to be shared. But wanting to "book now" is an action and most sites have them as a button.

[kaoD]

I will reword GP: if your <button> onClick navigates to another URL, your button is not a button but a link.