The main difference between the Apple charger MFi and PD is their function and purpose. MFi, short for \"Made for iPhone\/iPad\/iPod,\" is Apple's trademark license for external accessories made by its authorized accessory manufacturers. Mfi-certified chargers are better compatible with Apple devices, charge faster, and don't have incompatible pop-up alerts. PD, short for \"Power transfer,\" is a fast charging standard that allows for higher charging speeds and data transfer speeds. Therefore, MFi certification focuses more on compatibility, while PD focuses more on charging speed and efficiency.