What does Apple's mobile phone use to intercept phone messages?

1. First, find the Phone icon on the iPhone home screen, and then click Open.

2. Find the strange phone number you want to block in Recent Calls, and then click the "Details" icon on the right side of the phone number column.

3. Find the option "Block this calling number" at the bottom of the phone number profile information, and then click it.

4. Then click "Block Contacts" in the options that pop up at the bottom.