[sixpence]

Hello all

I have been lurking for a while now. This site is the most informative of all that I've found. I am not as technically literate as most of you are so your help with my fumbling questions would be appreciated.
1. What is the difference between a ball screw and a lead screw?
2. I think the ball screw from SKF is what I am looking for:diam 8mm :right hand lead 2.5mm:total length 936mm for the x axis

model designation from catalogue SH 8x2.5R

there does not seem to be any backlash elimination involved with the nut. 3. How do I eliminate backlash with this particular screw/nut assembly.
Am I heading in the right direction here .
In South Africa help seems to be on the sparce side.