I implemented a webpage that in practice was a dead end and it just said "Your registration is complete. Please press the button to go back." and there was a button to go back to the page from where the registration was. It might sound somewhat awkward but it turned out very natural and easy to understand and looked good. But it really should not have been a button but a link shouldn't it? Or is it acceptable to make a button instead of a link when it "feels right" to have a button instead of a link? Or is there any rule-of-thumb to know what should be a link and what's to be a button? I understand that buttons should be for submits but a button can also be an indication that something more important than just navigation is taking place e.g. "You are done with the registration." or likewise.
For instance, the use case "Ask question" here is an action that is an action that a link can make and any way it's implemented as a button.
Can you comment and/or answer when it is more right to use a button that a link for simple navigation that is not like form submits? I understand that links are used more in websites than in desktop apps, but desktop apps can also use links while it is sometimes more instructive to have a button that will open up a browser window. What do you think?