It helps to give the user a potentially high priority message, such as a new text message, voice mail or incoming phone call, either when the user gives the phone their attention, for example, by opening a flip phone or when running an application such as a game in the foreground.
It serves to draw the user's attention to a potentially high-priority message, such as a new text message, voicemail, or incoming phone call, either when the user gives the phone their focus, like opening a flip phone, or when running an application like a game in the foreground.