Note: some of this information is out of date with release of new iPhone models with USB-C built-in.
Apple makes a ton of money from “lightning” cables. The lightning connection is proprietary to Apple and third parties need to pay a licensing fee to use it. USB-C is better in every conceivable way (even by Apple’s own admission) and is a universal protocol. USB-C can be used to charge laptops (at potentially much higher wattage), drive multiple external 4K monitors, hard drives etc. The lightning cable is defunct.
Their chargers are deliberately confusing. Some of the new iPhones come with a lightning to USB-C cable to enable “fast charging”, however this means purchasing a brand new USB-C charger, which is no longer included. This needs to be at least 18w to enable fast charging (the usual ones are 5w). Why not just change the charging port on the iPhone to USB-C? Again, Apple have their own protocol for fast charging (USB Power Delivery or “PD”). Newer gallium nitride (GaN) chargers can charge at a much higher wattage (even charging laptops such as MacBooks or Dell XPS or the Microsoft Surface Pro) in a much smaller charging package – a potentially valuable purchase if your laptop can be charged via USB-C and you don’t just use it at home.
Complicating things even further, it appears that not all USB-C cables are created equal! Some are able to charge at higher wattage than others, some can carry DisplayPort protocol or even 4K video and there are even differences between speeds. See the diagram below and enjoy.
Edit: new iPhones and iPads have been updated with USB-C. However only certain “pro” models are eligible for “fast charging”. Price gauging?
https://www.howtogeek.com/509209/what-is-a-gan-charger-and-why-will-you-want-one/
