is messaging and texting the same?

Technically they're different I believe. Instant messaging uses the phones internet/data plan while texting sends the messages using the phone service. To me, they're basically the same but you have to be signed into the service to actually see the instant message while the person will always get the text if his phone is on and he's within his phone service coverage.

As tsar guesses, the underlying technologies are different. Texting uses SMS, an international telecommunication standard whereas IM can use any of a number of protocols http://en.wikipedia.org/wiki/Comparison_of_instant_messaging_protocols. With xmpp probably being the most likely vendor independent protocol

I can't quite pin down what apple messages uses, seems like its a hybrid of SMS and IM.

But as far as your friend is concerned they both require typing.