Makita Bench

whats the difference between drill drivers & impact drivers?

I'm a self employed joiner who also goes out to install in our customers homes. I do a lot of decking and have gone through 3 cordless drills in 4 years. The first was a ryobi 18v combi, then a hitachi 18v drill/driver & a makita 14.4v drill/driver the clutch in first gear went on two and the ryobi just burnt out when attempting to drill 80mm wholesaws for spotlights. I was recently speaking to a friend of mine who's a plumber and he started speaking highly of impact drivers? sure ive seen them for sale but never researched them for myself. I really need something that packs a punch but will it be redundant for the work on the bench? also. What brand should i buy? I've always tried to buy blue bosch budget permitting, but of course it depends whats on offer. But what do they do that drill/drivers dont? if im gonna spend £300 on an impact driver then i want a good un. Appreciate your help, kind regards.

what for the love of all that is holy has this to do with printers