How does one use an iPhone to send a text to another?

First, check to make sure the iPhone is turned on. Then, make sure you have reception. Look for the text messaging icon and tap it. Enter the phone number of the person you wish to text in the space clearly marked for the purpose. Remember most land line phones cannot accept text messages and try to use the person's cell phone number. Type in the message you wish to send and send it. If further instructions are needed, the Apple Support website gives step by step instructions for all models of iPhone including graphics.