Good question! This detail for each hero is visible when selecting the hero in the list and look at the top-right side, next to the hero category. There are five different hero classes, each with unique abilities and roles:
Champions - These heroes excel in dealing damage.
Commanders - They can boost your team's performance and strategies.
Geniuses - Masters of tactical maneuvers and traps..
Great Leaders - Provide overall team boosts and leadership qualities.
Manipulators - Experts at controlling the battlefield and disrupting enemies.
The class is the best way to know the usage of each hero in your team, and is also a way to make a good composition with various kind of heroes.