Destiny is a game that you fight the darkness so it doesn’t take over the whole solar system. your character is a person that has been dead for thousands of years and a ghost find you and brings you back to life and then in a series of missions you go to the heart of the darkness which is in a place called the black garden and destroy it. there is also different missions called strikes where you defeat other bosses, and then there is the crucible which is competitive multiplayer. (the traveler is the orb you see in the screen).