Notification icons are the small graphical symbols that appear on a device's screen to indicate that something has happened or is happening. They're used for everything from letting you know that you've received a new email or text message, to indicating that an app needs your attention.
Most notification icons are relatively self-explanatory — a envelope icon, for example, usually indicates that you have a new message — but some can be more confusing. Here's a quick rundown of some of the more common notification icons you might see on your Android device:
Envelope Icon: This indicates that you have a new message waiting, whether it's an email, text, or other type of communication.
Bell Icon: This is typically used as an indicator that there's something new waiting for you in an app. For example, many social media apps will use a bell icon to let you know when someone has liked or commented on one of your posts.
Exclamation Point Icon: An exclamation point inside of a triangle is often used as a warning symbol, and on Android devices it typically indicates that there's a problem with an app or system update. If you see this icon, it's worth taking a look at whatever message appears along with it to see if there's anything you need to do.
Circle Arrow Icon: This signifies that something is syncing or downloading in the background. It's commonly seen when files are being transferred wirelessly between two devices (like when sending pictures from your phone to your computer), but can also appear when updates are being downloaded or installed.
Battery Icon: The battery icon shows how much power remains in your device's battery. When it's fully charged, the battery icon will be solid; as the charge decreases, so does the level of coloration in the icon until it eventually turns completely gray when the battery is empty. Some devices also include additional information like estimated time remaining next to the battery icon