Peshat
The most superficial, literal interpretation, the first layer, the most mundane meaning.
Remez
The allegorical or symbolic meaning hiding just beneath the mundane layer.
Derash
The layer of the seeker, where comparative meaning can be drawn from a similar situation or presentation, i.e. “this is like…”
Sod
The hidden esoteric meaning that comes to light through inspiration or mystical revelation.