This game has four main roles which are support, tank, offense and defense. The players in offense have to deal with a lot of damage and since they have to face this much damage, they have only a few points.
Defense characters as the name suggest, have to avoid getting trapped and have to save and defend themselves from being beaten. Since, they have to defend themselves, and if not done well, they get only a few points and have the chance of sustaining many injuries also.
Tank characters have a high chance of getting more hit points as compared to all the other charcters because they have the special power of transferring the damage of the fire from their fellow team members and to themselves thus defeating the enemy team. There are many powers which the tank characters have and they have a lot of options as well to save themselves.
Support characters are supposed to provide their own team and thus make the enemy weaken. They do not have a lot of hit points and they also do not have to deal with a lot of problems or damage but they do play an important role in defeating their enemies.
Thus, this was all there was about the overwatch esports game and it is quite an interesting game to play and you will definitely enjoy playing this game as it is quite fun and adventurous as well. So download this game as soon as possible that you can and then there you go, you can start playing it!