racer vs driver

racer and driver both are nouns.

Word	Noun	Adjective	Verb	Adverb
racer	Yes	No	No	No
driver	Yes	No	No	No

As nouns, driver is a hypernym of racer; that is, driver is a word with a broader meaning than racer:

racer (noun)	driver (noun)
an animal that races	a golf club (a wood) with a near vertical face that is used for hitting long shots from the tee
slender fast-moving North American snakes	(computer science) a program that determines how a computer will communicate with a peripheral device
a fast car that competes in races	the operator of a motor vehicle
someone who drives racing cars at high speeds	a golfer who hits the golf ball with a driver
	someone who drives animals that pull a vehicle