what is the difference between parabola,projectile and trajectory?...experts plse answer my question fastly

Projectile :- 

A body thrown upward with a certain angle with the horizontal and certain initial horizontal velocity such that it falls only under the action of gravitational force is called a projectile.

For example a cannon ball. There are three basic parameters which completely define a projectile motion. Namely

1).total horizontal range

2. maximum height and

3. total time of flight

here 'd' is the horizontal range

∝ is the angle formed with horizontal plane

C is the point of maximum height

While 

The path described by a projectile flying or an object moving under the action of given forces is called its trajectory which is parabolic for a projectile motion.