Angle of attack is the angle of the wing to the relative wind. It determines the coefficient of lift, the amount of lift generated by your speed.
Aspect angle is basically the angle between an aircraft's fuselage and your line of sight.
Pursuit curves basically refer to pointing your aircraft's nose or lift vector at, ahead, or behind your target.
The angular difference between flight paths is the angle off tail or track crossing angle.
Terms can be confusing, sometimes I mix up aspect angle and angle off tail because they are similar. When common terms are used with no
reference to their actual meaning they become less useful and understanding the concepts becomes more difficult.