Areas in the game are zoned into 6 different zones: 1-19, 20-39, 40-59, 60-79, 80-98, 99+. It means a hero in the 20-39 zone will not share the same area as a hero in the 1-19 zone. This allows lower level players to not have to compete for kills with higher level players that are outside their zone's levels. Public Events & Social areas will still be shared by players of all levels.