TFP - Trade for Print is when the compensation for a photoshoot is the free images you receive. This can be a great trade when you are a new model and(or) can't afford test shoot.
Pro tip 1: Don't agree to every TFP shoot just because their free! Weed through the photographers and find ones who have great work and will add to your portfolio and image as a model.
Pro tip 2: Model Mayhem is a great way to come in contact with photogs willing to do TFP. BEWARE...some photographers on MM are total creeps and only want to exploit, so research them and be picky!