Links vs. buttons

When dealing with webpages, some usability experts say we should use links when the user is gonna get on a different page and buttons when the user makes an action.

I don’t really care. I don’t care because users don’t care.

Let’s get things a little further, what’s a button? Does it have to have borders? Different color?

Is a icon followed by a link really a link or a button? I see those things like buttons, others see it like “fancy links” or “descriptive links” or “visual links”.

One thing i agree with, though: forms should have “hard to miss” primary action button, you cannot put a link there mainly because it will not be a “primary action”, there are other links on a page so the weight of a “submit link” won’t be so different.