Airplane mode makes you iPad comply with airline regulations by disabling the wireless transmissions from the device. In particular, it disables transmission of Bluetooth, cellular data, WiFi, and GPS. Therefore your iPad will no longer be able to connect to the Internet during that time when airplane mode is turned on. This also mean that it will not be able to download nor send emails.
To enable Airplane mode, tap “Settings” from your Home screen. Then slide the airplane mode slider so that it displays “On”.
You can tell when airplane mode is on by the airplane icon on your top status bar. To disable airplane mode, simply slide that slider to the off position.