When a paladin gets to the third level, it can choose an oath from the paladins oaths. This oath gives certain abilities and spells that act "naturally" for the oath. This means that it doesn't need to be prepared, while the other spells do need a certain preparation before hand, a paladin needs to have certain spell slots and they must think about the spells they can cast before sleep (that's the preparation).
But something remains unclear for me. Do the spells of the paladin's oath work like cantrips for wizards and mages? Does using one still consume a spell slot?
I am actually playing a Paladin in a campaign, and I think those spells don't work like that, but I am not sure of that.