The idiomatic expression "to make a world of difference" means to have a significant impact or to cause something to be greatly different from what it was before. Full definition
It did make a world of a difference in my 5 months old when I began doing it. (babywisemom.com)
But it definitely makes a world of difference for my skin. (cheersj.com)
A comprehensive selection of plan designs and carrier choices also makes a world of difference when shopping for the lowest life insurance rates. (bestchoicelifeinsurance.com)