Read this: All major web browsers allow the user to open multiple information resources at the same time, either in different browser windows or in different tabs of the same window. Major browsers also include pop-up blockers to prevent unwanted windows from "popping up" without the user's consent.
Now answer this question, if there is an answer (If it cannot be answered, return "unanswerable"): Where do unwanted windows open in a browser?
unanswerable