When it says 'Certified' does that mean refurbished or some code for Apple authorized?

MFi certification is apple's license to use external accessories Made by its authorized accessory manufacturers.MFi certification is the abbreviation of apple Made for iPhone/iPad/iPod.
Apple has clear and mandatory requirements for all authorized distributors. For Apple's functional accessories products, it must sell certified and authorized brand accessories. Otherwise, the use of products without authorized accessories will cause damage to Apple products, and Apple will not make any warranty.