I'm not aware of a Magic: The Gathering keyword called "Protect." It's likely you're thinking of one of these:
Protection (e.g., "protection from red") is the real evergreen keyword. It means the permanent can't be Damaged, Enchanted/Equipped, Blocked, or Targeted by anything matching that quality—remembered as DEBT. The common mistake: protection doesn't stop everything. It won't counter sacrifice effects, "destroy all" board wipes that don't target, or trample damage being assigned (though it does prevent the damage itself). It also doesn't remove auras already attached—those simply fall off as a state-based action.
There's also Ward, which taxes opponents who target your permanent (paying a cost or the spell/ability is countered). And Hexproof/Shroud prevent targeting entirely.
If you tell me the exact card or context, I can pin down which mechanic you mean and explain its Commander relevance precisely.