A projectile is an object in flight after being projected or thrown and this motion is called Projectile Motion. For example, the motions of a cricket ball, or baseball.
In other words. the motion of a projected object in flight is known as projectile motion which is a result of 2 separate simultaneously occurring components of motion.
One component is along a horizontal direction without any acceleration (as no force acting in this direction) and the other is along the vertical direction with constant acceleration due to the force of gravity (considering air resistance as negligible). In a special post on this website, we discussed and derived a couple of projectile motion equations. [Derivation of projectile equations]
The trajectory of this projectile motion is a parabola.