What is the diff between Propagator/Activator

and how do you prepare each.

TIA
Tim

From what I understand, the only difference is the number of viable yeast cells that come in the package. So for Activators, you should make a starter, for Propagators, you definitely need to make a starter.

http://www.wyeastlab.com/hb_products.cfm
The PROPAGATOR™ has a minimum of 25 billion cells of pure yeast, plus an internal nutrient packet. The PROPAGATOR™ is designed to inoculate a one liter starter* before adding to five gallons of wort (up to 1.060 SG).

The Activator™ has a minimum of 100 billion cells of pure, ready-to-pitch yeast, plus an internal nutrient packet. The Activator™ is designed to inoculate five gallons of wort (up to 1.060 SG) providing the pitching rate recommended by professional brewers.

Wyeast intends for the activator to be directly pitched and the propagator to be used for making a starter when used for the same beer....you may want to make a starter either way depending on your preferences for cells pitched and OG of wort. JZ has a calculator for pitching volume @ www.mrmalty.com