Joke Collection Website - Public benefit messages - Why did iMessage and SMS have been sent when iPhone4 sent SMS?

Why did iMessage and SMS have been sent when iPhone4 sent SMS?

You can open iMessage in Settings → Information, and you can receive it with your mobile phone number Apple ID. When sending a short message, if the contact you choose has activated iMessage, iPhone will automatically use iMessage to send it. There is no short message fee for sending iMessage information, and effective wireless network or cellular data is required for sending and receiving.