The protection ability is often explained by using the acronym DEBT, which stands for Damage, Enchanting / Equipping, Blocking and Targeting.

Protection from :
D- Damage from sources of that quality is prevented.
E- Enchantments / Equipment of that quality can not enchant / equip the protected permanent.
B- The creature with protection can not be blocked by creatures of that quality.
T- Spells and abilities of that quality that target can not target the permanent with protection.

So far there has been just one card printed with the “Protection from Everything’ ability, Progenitus from Conflux. The important thing to keep in mind is that this protection ability works like others protection abilities, the only difference is that applies to any object with any quality. For example, Progenitus cannot be targeted by the enters the battlefield ability of Sower of Temptation, because that ability targets. But Progenitus can still be destroyed by spells that do not deal damage or target, like Day of Judgment.