This 18W charger from Apple showcases the developments that have been made in the charging world. It kicks out more power than their older style 5W USB Power Adatpers getting your iPhone or iPad up to full charge in a much faster time. The iPhone 8 and newer iPhones and take advantage of it's fast charging capabilities.
In case you haven't noticed, these don't have a USB port on them. They have a USB-C port. USB-C cables can be purchased seperately or if you want a USB-C to Lightning cable (as well as the plug) click here.