pop-up (book, toaster, etc.)
General term for objects or mechanisms that spring up or open automatically, such as pop-up books, toasters, or tents.
I bought a pop-up picture book for my child.
This toaster pops up when the toast is done.
pop-up (computing)
In computing, a small window or menu that appears suddenly on screen, often for ads, notifications, or context menus.
Pop-up ads frequently appear on the website.
You can block pop-ups in the settings.