Notifications on your android device

Some of the default icons that the status bar would have include the Time, Battery level indicator, Network strength indicator, Data network connection icon and Alarm all on the right side. There are even the connectivity icons shown in the status bar:

• Wi-Fi icon
• Bluetooth icon
• GPS tracker icon
• Airplane mode icon
• “Network name” icon on the extreme left

The left side contains the instant notifications that appear in accordance to the functions. A limited number of notifications icons are shown in the status bar, and if it exceeds that number, an icon showing a Plus sign along with the notification count would show up.

Here are some of the basic status icons that frequently would appear in the status bar:

• Mail icon: New Message on Gmail App
• A Smiley: A new Text or Multimedia received message
• An icon with Exclamation mark: Problem in delivery of SMS or MMS
• Icon with “Talk” word: New Message on Google Talk
• Phone icon: New Voicemail
• Date in Calendar: Upcoming event listed in Calendar
• A refresh icon: Data sync is in progress
• A triangular icon with Exclamatory mark: Problem with signing into the account, or syncing
• Storage disk with Exclamation mark: The storage SD card is full
• Wi-Fi icon with Question mark: Open Wi-Fi network is available. This shows only when you have the Wi-Fi connectivity turned on.
• A USB icon: Phone USB cable connective active
• A Blue USB icon: This indicates that the phone is sharing its data connection with the computer via USB, which we call as USB tethering.
• A Blue Wi-Fi icon: This indicates that the phone is sharing its data connection to the computer or other devices by becoming a personal Wi-Fi hotspot, and we call it Wi-Fi tethering.
• A Blue round icon with a center dot: This indicates that the phone has multiple connections on at the same time.
• Plus icon with a number: Multiple notifications not displayed
• Green call icon: Voice call in progress
• Blue call icon: Voice call in progress using the Bluetooth headset
• Missed call icon
• Green call + pause icon: Call on hold
• Call with an arrow mark: Call forwarding is active
• Music Play icon: Song is being played
• File with “up” arrow mark: Uploading data
• File with “down” arrow mark: Downloading data
• File with a check icon: Download completed
• A white key icon: Connected to a Virtual Private Network
• A grey key icon: Disconnected from a Virtual Private Network
• Triangle icon with up and down arrows: Network data limit threshold reached or exceeded
• Market icon with Android robot: Update available for Application
• Android robot with down arrow: System update available
• SIM with Exclamation mark: SIM-card is not installed or placed properly
• Micrphone icon with a diagonal line: The Microphone of the phone is muted
• Sound icon with an X – The ringer of the phone is silenced

There are several other icons that appear based on the applications that you download from the Android Play Store (previously Android Market). One of them is the Facebook messenger chat notification which appears just like the Google Talk icon when you receive any message from your Facebook friends.
The status icons in the status bar appear even based on the phone. For example, the Motorola Droid Razr would have the Data Manager icon always shown if you have the data network connection disabled.
Apart from the various status icons, one of the important range of icons that keep changing are the Data network connection icons which lets the user know about the network to which the phone is connected to, ranging from GPRS to 4G LTE. The icon with the shining or darkened arrow marks would indicate whether the data network connection is currently active or not.
Note: Many of the icons would just the users know the status of the phone or activity, but a few would take you to the particular app. You would need to check the Notification panel to see if there is any extra function or shortcut available for the icon that appeared on the status bar.