projectile motion plz sir i dont understan what are these

Projectile motionis a form ofmotionin which an object or particle (called aprojectile) is thrown near the earth's surface, andit moves along a curved path under the action ofgravityonly.The only force of significance that acts on the object is gravity, which acts downward to cause a downward acceleration. There are no horizontal forces needed to maintain the horizontal motion – consistent with the concept of inertia.