Audio/Headphone Jack: Used to plug in your headset or headphones.
Back Button: Used to go back one screen.
Earpiece Speaker: Listen to audio or phone calls from here.
Front Camera: Used for taking pictures and recording videos.
Home Button: Navigates you back to the main Home screen.
Microphone: Built-in microphone used for phone calls and voice commands.
Power/Lock Button: Press to lock or unlock the touchscreen. Hold down to turn the device on or off.
Recent Apps Button: Opens a list of the apps you've opened recently.
Touchscreen: Used to navigate your device.
USB/Charging Port: Used to charge your battery and connect your phone to other devices.
Volume Buttons: Adjusts the volume on your device.