Final answer:
A new browser window or tab that appears in front of the current window is typically called a pop-up. Pop-ups are often considered intrusive and can be blocked by browsers or plugins.
Step-by-step explanation:
When a new browser window or tab appears in front of your current browser window, it is typically called a pop-up. Pop-ups are windows that open without the user's consent or expectation and often display advertisements or additional content.
Pop-ups are sometimes considered intrusive and can be blocked by browsers or plugins to improve user experience and prevent potential security risks.