Toasts serve as low-priority system notifications or messages from background services in mobile applications, particularly on Android devices. They are commonly used to convey information that might require user attention, such as prompts to update the device ("Update your iPhone") or notifications from background services ("No Email client found"). Unlike snackbars, which only appear one at a time, multiple toasts can appear on top of each other, potentially leading to a more noticeable and sometimes overwhelming notification experience.

It's important to note that the inability to dismiss toasts by swiping can be annoying to users. So, always consider the frequency and relevance of using toasts to avoid overwhelming users with too many overlapping notifications.