A fresh ham is an uncured, uncooked rear leg of a pig. Cooked as a roast, for instance, the results are what one would expect from "roast pork". It can be smoked, however. It can also be cured first, given sufficient time. If cured then smoked it comes out like "ham" - though better than what one normally buys as ham at the market. This is a recipe I wrote for cured, smoked ham some time ago. It takes 10 days for the cure but one could do a half ham.
Alternatively, one can get a ready-to-cook ham (it's been cured first, or cured and lightly smoked, depending) and smoke/cook it. Or one can get an already cured/smoked/cooked ready-to-eat ham and smoke it further (or not) during reheating.