In North America, professional hockey works like this
National Hockey League (top tier)
American Hockey League (sends players up to NHL)
East Coast Hockey League (sends players up to AHL)
The AHL and ECHL are the only two minor leagues recognized by the NHL collective bargaining agreement, which means anyone signed to an NHL development contract must first report to an AHL or ECHL club.
Each NHL team has one AHL affiliate and one ECHL affiliate.