Motion: 

the state in which one objects distance is changing from another object.

Reference Point: 

a place or object used for comparison to determine if something is in motion.  A point to which I refer, can be on the object itself.

Speed: 

the distance the object travels in one unit of time.

Position  

 the place where something is.

Delta

change

Distance:

 how far something travels or the amount of change.

Final

ending point

Inital

Beginning point

Final

symbol

f

Inital

symbol

i

Delta

symbol

Δ

Position

x