Does 'Resist Magic' affect defensive spells, like Healing? What about potions or poisons?

Does 'Resist Magic' affect offensive spells against the player only? Or does it also affect defensive spells, like Healing, Lesser Ward, etc.?

Also, does Skyrim's 'Resist Magic' act like Oblivion's 'Resist Magic', where it also affects poisons? What about potions?

Thankfully, Skyrim does not suffer like Oblivion from all those unintuitive effects.

The one exception is magic ABSORB (not resist). It is available from the Breton's activated racial ability, the Atronach standing stone, and an Alteration perk. Even then, it only causes your conjurations to fail, and does not affect your healing magic, potions, etc. My Breton character simply doesn't conjure anything and enjoys full effect from everything while laughing off mage NPCs. If you want to conjure things and resist magic, simply avoid magic absorb and steer yourself towards hitting the 80% RESIST magic cap.

No. Resist magic does not affect healing spells or anything such as that. It only affects harmful spells. Second, not 100% sure, but I do not think that resist magic would resist poisons, unless said poison was from a spell. If it was from alchemy, or something else, then it would deal 100% of the poison damage.