with a cartage you wet the polyester with juice, with a drip tip, you drip a drop or two when the atty dries up, with a carto, there is no atomizer, just a wire that gets hot, and it is wrapped in polyester
if you want to "direct drip" you use a drip tip, cause you can drip through the hole in the drip tip, but you do not use the cartage anymore, the drip tip replaces it
I use a drip tip with a carto, cause I like the feel and they are easier to pull out to load the carto
HTH