leadscrew, acme screw, threaded rod, ballscrew

Hi,

Hope someone can take a little time to clarify some normenclature, to
distinquish cleary between these terms.

When one mention leadscrew, does it refers to all kind of screws that
are used to drive linear motion components (including acme screw,
ball screw, threaded rod) or are they a special type of threaded rod
made specially for linear motion drives?

Is the leadscrew used in the sherline a threaded rod or a screw
configured specially for linear drive?

Thanks

Al