Possible Duplicate:
HTML buttons vs hyperlinks for navigation
HTML links were born to show internal or external pages, or take you to a specific page position (anchors).
Now, with the popularization of AJAX, some developers started to use them to display dynamic content, perform actions like save, delete, etc. In some GUIs, even they are used to display dialogs (twitter).
I know that we should always try to use blue in link's text. That's can be taken like a standar.
But, is there a standard which says for what stuff we should use link, or in which scenarios to avoid them and instead use buttons, for example?
My question is because I'm starting to get confused with links. I do not know what to expect from them. Sometimes I use the option "Open link in a new tab", but then I get surprised that the link was just a kind of button. Twitter is an example of this frustration for me.