What is airplane mode on my iphone 5?

And what does it do when you turn it on?

It prevents your iPhone from transmitting or receiving wireless signals that will affect the operations in the plane such as Internet surfing or sending or receiving calls or texts.

It's to turn off the whole connection things, so, no Internet, and no telephone provider

You can still play with apps, but you can't be on the Internet surfing, and you can't make a phone call

It turns off the Wi-Fi, like your not allowed to use on an airplane.

The name in part explains it. When activated it disables the radios that the iPhone has, the cell signal (prevents calls, texts, data) & Wi-Fi signal (of course no internet). Primarily used in planes, hence the name.

The airplane mode makes it so that there will not be any communications from your phone to the ground. Airplane mode is required on planes because they will mess up the planes communications. When you turn it on, you will not be able to search the web but you will be able to search the web but you will be able to still use offline apps that do not use an internet connection.

Um, this is your first phone isn't it?