How does gravity affect projectile motion?

Gravity has no effect on horizontal motion, but it causes accelerated vertical motion downward.  The result of this combination is that if the projectile is launched with ANY horizontal motion ... not straight up or straight down ... then its motion from the time it's launched until the time it hits the ground is always a part of a parabola.

lets take a bow and arrow 4 exampleu shoot itthe arrow goes 30 feet and then it hits the ground because of gravity without gravity...the arrow would go forevermore onward