will restoring the iphone delete everything in the phone?

Yes, restoring means it's going to restore your phone to factory settings. Now, if you're restoring from a backup, then it's going to replace whatever is on the device with whatever is in the backup

That's what I said. If you're just restoring the phone in itunes by pressing the 'restore iphone' button and do not restore from a backup, it WILL wipe your phone and restore it to factory settings. It will be exactly like it was when you got it out of the box