Spells

[Guymon71]

If anything but lands count as spells can mindbreak trap count as a boardwipe fir the opponents if you want

[Remillo]

Spells only exist on the Stack.  Usually, permanents, instants and sorceries are originally cast as spells, where they exist on the stack until they resolve.  Once a Creature spell resolves, it becomes a Permanent instead of a Spell.  Same for Planeswalkers, Artifacts and Enchantments.  Mindbreak Trap can't effect them.