The difference is that the first of them we must complete on our own, while in the second we can help the members of our Squad, regardless of whether they are on our list of friends or not.
What these challenges ask us to do is inflict damage on enemies while riding in a vehicle like a car. These ground vehicles only appear in Solitaire, Duet, and Squadron game modes. Finding them is very simple; there are many throughout the island, mainly in named locations, and in areas where there are roads and asphalt (cars are not in the middle of the field).
To inflict damage on an enemy while driving, we must go in one of the passenger seats. Once this is done, if we press the aim button, our character will take half a body out the window, and we can shoot with the weapon that we have equipped.
The simplest way to inflict damage on enemies while driving is to take down an opposing player (in Duos or Squads), jump into a nearby vehicle, switch to one of the passenger seats, and shoot while they’re down.
Another crazier option is to simply ride any vehicle and roam the stage looking for enemy players. As soon as we find any, we switch to any passenger seat, and we try to shoot them.
We can also inflict damage from motorboats, both from the passenger and pilot seats, launching rockets.