Cordless, battery-powered drill/driver: As a 20 V drill it runs on a rechargeable lithium-ion battery, so you get mobility and don’t need a power socket while working. That makes it handy for sites without stable mains, or when drilling/fastening away from fixed power.
Brushless motor: Unlike older “brushed” motors (with carbon brushes that wear out), a brushless motor uses electronic switching — meaning: