Friendship Points, are often abreviated to FP. FP is a useful tool obtained by greeting to your friends and random strangers, everytime you greet someone random, you get 2 FP, if you greet a friend, you get 5 FP and finaly if you send thanks to a fellow player who aided you in battle you get 3 FP. FP's only purpose is to open normal dino cages.
Now, normal dino cages give weak normal dinosaurs that don't have much use to anyone, except for food. Because of this reason everyone greets daily to open more dino cages so that they can level up their Dinosaurs quicker. A vital skill you must learn to become a decent player is to level up dinosaurs as you level up yourself, that way you are always on top of things and you can beat higher level players.
During some events additional FP will be given for various tasks. Sending greetings to players who aided in battle gives 3 + 7 extra FP.