[Chevelle-List] Tech question

[Craig & Cerena Robertson]

I was in the process of checking Advance Auto for Upper and Lower Ball Joint and Control Arm Bushings.  They have some terms that I have not a clue.  Hope someone can set me straight.     When looking for Ball Joints they also list the item Ball Joint with the word Axial or Radial after it in the list.  What do they mean Axial and Radial.      I also notice that you can purchase the Control Arm Shaft or just the Bushings.  Should I replace the shaft while I at it or not.  Thanks for you help.     (The man with a dumb question)