The modified weapon skill is what determines if you can hit or block the enemy. The difference between your skill and your enemies skill changes the chance of hitting or blocking.
Not that mod weapon skill does not effect how hard you hit.
Individual weapon classes do not effect your chance of hitting (unless they mod your weapon skill).
Some weapon classes do affect the chances of crit hits and what is the impact of those hits.
e.g. Axe can stun and dual wield can poison and staff allows temps to mediate.
Type /wand or /dagger etc to see the modifying stats of various weapon types.