Trajectory: The path the bullet takes.
Page 24: The path of the projectile in flight.
Wind drift: The affect of wind on the bullet.
Page 8: Bullet flight is affected by wind drift.
Recoil: Is the rearward force a firearm exerts when fired.
Page 10: The book does not give a clear definition of recoil but explains what it is. The energy that that moves the gun rearward into the shooters shoulder.
Velocity: Is the speed of which a bullet travels.